Organ movement refactor *Un-nullspaces your organs* (#79687)

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closes #53931, #70916, #53931

## About The Pull Request

Organs were previously stored in nullspace. Now they are stored in their
prospective bodyparts. Bodyparts are now stored in the mob.

I've also had to refactor a lot of code concerning organ movement.
Previously, organs were only moved into bodyparts once the bodyparts
were removed. To accomodate this change, two major distinctions have
been made:

**Bodypart removal/insertion**
Called only when an organ is taken out of a bodypart. Bodypart overlays,
damage modifiers or other changes that should affect a bodypart itself
goes here.

**Mob insertion/removal**
Called when an organ is removed from a mob. This can either be directly,
by taking the organ out of a mob, or by removing the bodypart that
contains the organ. This lets you add and remove organ effects safely
without having to worry about the bodypart.

Now that we controle the movement of bodyparts and organs, we can fuck
around with them more. Summoning someones head or chest or heart will
actually kill them now (and quite violently I must say (chest summoning
gibs lol)).


https://github.com/tgstation/tgstation/assets/7501474/5efc9dd3-cfd5-4ce4-b70f-d0d74894626e

I´ve also added a unit test that violently tears apart and reconstructs
a person in different ways to see if they get put toghether the right
way

This will definitely need a testmerge. I've done a lot of testing to
make sure interactions work, but more niche stuff or my own incompetence
can always slip through.

## Why It's Good For The Game

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A lot of organ work is quite restricted. You can't C4 someones heart,
you cant summon their organs and a lot of exceptions have to be made to
keep organs in nullspace. This lets organs (and bodyparts) play more
nicely with the rest of the game. This also makes it a lot easier to
move away from extorgans since a lot of their unique movement code has
been removed and or generalized.

I don't like making PRs of this size (I'm so sorry reviewers), but I was
in a unique position to replace the entire system in a way I couldn't
have done conveniently in multiple PRs

## Changelog

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🆑
refactor: Your organs are now inside your body. Please report any issues
with bodypart and organ movement, including exotic organ, on github and
scream at me
fix: Cases of unexpected organ movement, such as teleporting bodyparts
and organs with spells, now invokes a proper reaction (usually violent
death)
runtime: Fixes HARS runtiming on activation/deactivation
fix: Fixes lag when species swapping
/🆑

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your name to the right of the first 🆑 if you want to overwrite your
GitHub username as author ingame. -->
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icon ingame) and delete the unneeded ones. Despite some of the tags,
changelogs should generally represent how a player might be affected by
the changes rather than a summary of the PR's contents. -->

code/__DEFINES/organ_movement.dm

@@ -0,0 +1,4 @@
+/// Delete the organ if replaced
+#define DELETE_IF_REPLACED (1<<0)
+/// When deleting a brain, we don't delete the identity and the player can keep playing
+#define NO_ID_TRANSFER (1<<1)

code/__DEFINES/traits/sources.dm

@@ -275,5 +275,7 @@
 
 #define ANALYZER_TRAIT "analyzer_trait"
 
+/// Trait from an organ being inside a bodypart
+#define ORGAN_INSIDE_BODY_TRAIT "organ_inside_body"
 /// Trait when something was labelled by a pen.
 #define PEN_LABEL_TRAIT "pen_label"

code/__HELPERS/mobs.dm

@@ -654,11 +654,6 @@ GLOBAL_LIST_EMPTY(species_list)
 	if(isliving(occupant))
 		mob_occupant = occupant
 
-	else if(isbodypart(occupant))
-		var/obj/item/bodypart/head/head = occupant
-
-		mob_occupant = head.brainmob
-
 	else if(isorgan(occupant))
 		var/obj/item/organ/internal/brain/brain = occupant
 		mob_occupant = brain.brainmob

code/datums/ai/generic/generic_behaviors.dm

@@ -359,6 +359,10 @@
 			continue
 		if(thing.IsObscured())
 			continue
+		if(isitem(thing))
+			var/obj/item/item = thing
+			if(item.item_flags & ABSTRACT)
+				continue
 		possible_targets += thing
 	if(!possible_targets.len)
 		finish_action(controller, FALSE)

code/datums/bodypart_overlays/mutant_bodypart_overlay.dm

@@ -93,8 +93,8 @@
 	CRASH("External organ has no feature list, it will render invisible")
 
 ///Give the organ its color. Force will override the existing one.
-/datum/bodypart_overlay/mutant/proc/inherit_color(obj/item/bodypart/ownerlimb, force)
-	if(isnull(ownerlimb))
+/datum/bodypart_overlay/mutant/proc/inherit_color(obj/item/bodypart/bodypart_owner, force)
+	if(isnull(bodypart_owner))
 		draw_color = null
 		return TRUE
 
@@ -103,14 +103,14 @@
 
 	switch(color_source)
 		if(ORGAN_COLOR_OVERRIDE)
-			draw_color = override_color(ownerlimb.draw_color)
+			draw_color = override_color(bodypart_owner.draw_color)
 		if(ORGAN_COLOR_INHERIT)
-			draw_color = ownerlimb.draw_color
+			draw_color = bodypart_owner.draw_color
 		if(ORGAN_COLOR_HAIR)
-			if(!ishuman(ownerlimb.owner))
+			if(!ishuman(bodypart_owner.owner))
 				return
-			var/mob/living/carbon/human/human_owner = ownerlimb.owner
-			var/obj/item/bodypart/head/my_head = human_owner.get_bodypart(BODY_ZONE_HEAD) //not always the same as ownerlimb
+			var/mob/living/carbon/human/human_owner = bodypart_owner.owner
+			var/obj/item/bodypart/head/my_head = human_owner.get_bodypart(BODY_ZONE_HEAD) //not always the same as bodypart_owner
 			//head hair color takes priority, owner hair color is a backup if we lack a head or something
 			if(my_head)
 				draw_color = my_head.hair_color

code/datums/components/crafting/crafting.dm

@@ -106,6 +106,10 @@
 	for(var/atom/movable/AM in range(radius_range, a))
 		if((AM.flags_1 & HOLOGRAM_1) || (blacklist && (AM.type in blacklist)))
 			continue
+		if(isitem(AM))
+			var/obj/item/item = AM
+			if(item.item_flags & ABSTRACT) //let's not tempt fate, shall we?
+				continue
 		. += AM
 
 /datum/component/personal_crafting/proc/get_surroundings(atom/a, list/blacklist=null)

code/datums/diseases/gastrolisis.dm

@@ -40,7 +40,7 @@
 			var/obj/item/organ/internal/eyes/eyes = locate(/obj/item/organ/internal/eyes/snail) in affected_mob.organs
 			if(!eyes && SPT_PROB(2.5, seconds_per_tick))
 				var/obj/item/organ/internal/eyes/snail/new_eyes = new()
-				new_eyes.Insert(affected_mob, drop_if_replaced = TRUE)
+				new_eyes.Insert(affected_mob)
 				affected_mob.visible_message(span_warning("[affected_mob]'s eyes fall out, with snail eyes taking its place!"), \
 				span_userdanger("You scream in pain as your eyes are pushed out by your new snail eyes!"))
 				affected_mob.emote("scream")

code/datums/dna.dm

@@ -526,7 +526,6 @@ GLOBAL_LIST_INIT(total_uf_len_by_block, populate_total_uf_len_by_block())
 		update_body(is_creating = TRUE)
 		update_mutations_overlay()// no lizard with human hulk overlay please.
 
-
 /mob/proc/has_dna()
 	return
 

code/datums/mutations/body.dm

@@ -500,14 +500,16 @@
 
 	var/obj/item/organ/internal/brain/brain = owner.get_organ_slot(ORGAN_SLOT_BRAIN)
 	if(brain)
+		brain.Remove(owner, special = TRUE)
 		brain.zone = BODY_ZONE_CHEST
+		brain.Insert(owner, special = TRUE)
 
 	var/obj/item/bodypart/head/head = owner.get_bodypart(BODY_ZONE_HEAD)
 	if(head)
 		owner.visible_message(span_warning("[owner]'s head splatters with a sickening crunch!"), ignored_mobs = list(owner))
 		new /obj/effect/gibspawner/generic(get_turf(owner), owner)
-		head.dismember(dam_type = BRUTE, silent = TRUE)
 		head.drop_organs()
+		head.dismember(dam_type = BRUTE, silent = TRUE)
 		qdel(head)
 	RegisterSignal(owner, COMSIG_ATTEMPT_CARBON_ATTACH_LIMB, PROC_REF(abort_attachment))
 

code/datums/quirks/negative_quirks/junkie.dm

@@ -134,7 +134,7 @@
 			smoker_lungs = /obj/item/organ/internal/lungs/smoker_lungs
 	if(!isnull(smoker_lungs))
 		smoker_lungs = new smoker_lungs
-		smoker_lungs.Insert(carbon_holder, special = TRUE, drop_if_replaced = FALSE)
+		smoker_lungs.Insert(carbon_holder, special = TRUE, movement_flags = DELETE_IF_REPLACED)
 
 /datum/quirk/item_quirk/junkie/smoker/process(seconds_per_tick)
 	. = ..()

code/datums/quirks/negative_quirks/prosthetic_organ.dm

@@ -49,7 +49,7 @@
 	medical_record_text = "During physical examination, patient was found to have a low-budget prosthetic [slot_string]. \
 	<b>Removal of these organs is known to be dangerous to the patient as well as the practitioner.</b>"
 	old_organ = human_holder.get_organ_slot(organ_slot)
-	if(prosthetic.Insert(human_holder, special = TRUE, drop_if_replaced = TRUE))
+	if(prosthetic.Insert(human_holder, special = TRUE))
 		old_organ.moveToNullspace()
 		STOP_PROCESSING(SSobj, old_organ)
 

code/datums/quirks/negative_quirks/tin_man.dm

@@ -30,7 +30,7 @@
 	for(var/organ_slot in possible_organ_slots)
 		var/organ_path = possible_organ_slots[organ_slot]
 		var/obj/item/organ/new_organ = new organ_path()
-		new_organ.Insert(human_holder, special = TRUE, drop_if_replaced = FALSE)
+		new_organ.Insert(human_holder, special = TRUE, movement_flags = DELETE_IF_REPLACED)
 
 /datum/quirk/tin_man/post_add()
 	to_chat(quirk_holder, span_boldannounce("Most of your internal organs have been replaced with surplus prosthetics. They are fragile and will easily come apart under duress. \

code/datums/station_traits/positive_traits.dm

@@ -334,7 +334,7 @@
 			ai.eyeobj.relay_speech = TRUE //surveillance upgrade. the ai gets cybernetics too.
 		return
 	var/obj/item/organ/internal/cybernetic = new cybernetic_type()
-	cybernetic.Insert(spawned, special = TRUE, drop_if_replaced = FALSE)
+	cybernetic.Insert(spawned, special = TRUE, movement_flags = DELETE_IF_REPLACED)
 
 /datum/station_trait/luxury_escape_pods
 	name = "Luxury Escape Pods"

code/datums/status_effects/neutral.dm

@@ -522,7 +522,7 @@
 				return
 			if(prob(1))//low chance of the alternative reality returning to monkey
 				var/obj/item/organ/external/tail/monkey/monkey_tail = new ()
-				monkey_tail.Insert(human_mob, drop_if_replaced = FALSE)
+				monkey_tail.Insert(human_mob, movement_flags = DELETE_IF_REPLACED)
 			var/datum/species/human_species = human_mob.dna?.species
 			if(human_species)
 				human_species.randomize_active_features(human_mob)

code/game/machinery/dna_infuser/organ_sets/carp_organs.dm

@@ -48,7 +48,7 @@
 	AddElement(/datum/element/noticable_organ, "teeth are big and sharp.", BODY_ZONE_PRECISE_MOUTH)
 	AddElement(/datum/element/organ_set_bonus, /datum/status_effect/organ_set_bonus/carp)
 
-/obj/item/organ/internal/tongue/carp/on_insert(mob/living/carbon/tongue_owner)
+/obj/item/organ/internal/tongue/carp/on_mob_insert(mob/living/carbon/tongue_owner, special, movement_flags)
 	. = ..()
 	if(!ishuman(tongue_owner))
 		return
@@ -57,12 +57,14 @@
 		return
 	var/datum/species/rec_species = human_receiver.dna.species
 	rec_species.update_no_equip_flags(tongue_owner, rec_species.no_equip_flags | ITEM_SLOT_MASK)
-	var/obj/item/bodypart/head/head = human_receiver.get_bodypart(BODY_ZONE_HEAD)
-	head.unarmed_damage_low = 10
-	head.unarmed_damage_high = 15
-	head.unarmed_effectiveness = 15
 
-/obj/item/organ/internal/tongue/carp/on_remove(mob/living/carbon/tongue_owner)
+/obj/item/organ/internal/tongue/carp/on_bodypart_insert(obj/item/bodypart/limb)
+	. = ..()
+	limb.unarmed_damage_low = 10
+	limb.unarmed_damage_high = 15
+	limb.unarmed_effectiveness = 15
+
+/obj/item/organ/internal/tongue/carp/on_mob_remove(mob/living/carbon/tongue_owner)
 	. = ..()
 	if(!ishuman(tongue_owner))
 		return
@@ -71,7 +73,10 @@
 		return
 	var/datum/species/rec_species = human_receiver.dna.species
 	rec_species.update_no_equip_flags(tongue_owner, initial(rec_species.no_equip_flags))
-	var/obj/item/bodypart/head/head = human_receiver.get_bodypart(BODY_ZONE_HEAD)
+
+/obj/item/organ/internal/tongue/carp/on_bodypart_remove(obj/item/bodypart/head)
+	. = ..()
+
 	head.unarmed_damage_low = initial(head.unarmed_damage_low)
 	head.unarmed_damage_high = initial(head.unarmed_damage_high)
 	head.unarmed_effectiveness = initial(head.unarmed_effectiveness)
@@ -110,13 +115,13 @@
 	AddElement(/datum/element/organ_set_bonus, /datum/status_effect/organ_set_bonus/carp)
 	AddElement(/datum/element/noticable_organ, "seem%PRONOUN_S unable to stay still.")
 
-/obj/item/organ/internal/brain/carp/on_insert(mob/living/carbon/brain_owner)
+/obj/item/organ/internal/brain/carp/on_mob_insert(mob/living/carbon/brain_owner)
 	. = ..()
 	cooldown_timer = addtimer(CALLBACK(src, PROC_REF(unsatisfied_nomad)), cooldown_time, TIMER_STOPPABLE|TIMER_OVERRIDE|TIMER_UNIQUE)
 	RegisterSignal(brain_owner, COMSIG_MOVABLE_Z_CHANGED, PROC_REF(satisfied_nomad))
 
 //technically you could get around the mood issue by extracting and reimplanting the brain but it will be far easier to just go one z there and back
-/obj/item/organ/internal/brain/carp/on_remove(mob/living/carbon/brain_owner)
+/obj/item/organ/internal/brain/carp/on_mob_remove(mob/living/carbon/brain_owner)
 	. = ..()
 	UnregisterSignal(brain_owner, COMSIG_MOVABLE_Z_CHANGED)
 	deltimer(cooldown_timer)

code/game/machinery/dna_infuser/organ_sets/fox_organs.dm

@@ -6,7 +6,7 @@
 	visual = TRUE
 	damage_multiplier = 2
 
-/obj/item/organ/internal/ears/fox/on_insert(mob/living/carbon/human/ear_owner)
+/obj/item/organ/internal/ears/fox/on_mob_insert(mob/living/carbon/human/ear_owner)
 	. = ..()
 	if(istype(ear_owner) && ear_owner.dna)
 		color = ear_owner.hair_color
@@ -14,7 +14,7 @@
 		ear_owner.dna.update_uf_block(DNA_EARS_BLOCK)
 		ear_owner.update_body()
 
-/obj/item/organ/internal/ears/fox/on_remove(mob/living/carbon/human/ear_owner)
+/obj/item/organ/internal/ears/fox/on_mob_remove(mob/living/carbon/human/ear_owner)
 	. = ..()
 	if(istype(ear_owner) && ear_owner.dna)
 		color = ear_owner.hair_color

code/game/machinery/dna_infuser/organ_sets/goliath_organs.dm

@@ -66,7 +66,7 @@
 	AddElement(/datum/element/noticable_organ, "arm is just a mass of plate and tendrils.", BODY_ZONE_CHEST)
 	AddElement(/datum/element/organ_set_bonus, /datum/status_effect/organ_set_bonus/goliath)
 
-/obj/item/organ/internal/brain/goliath/on_insert(mob/living/carbon/brain_owner)
+/obj/item/organ/internal/brain/goliath/on_mob_insert(mob/living/carbon/brain_owner)
 	. = ..()
 	if(!ishuman(brain_owner))
 		return
@@ -78,7 +78,7 @@
 	hammer = new/obj/item/goliath_infuser_hammer
 	brain_owner.put_in_hands(hammer)
 
-/obj/item/organ/internal/brain/goliath/on_remove(mob/living/carbon/brain_owner)
+/obj/item/organ/internal/brain/goliath/on_mob_remove(mob/living/carbon/brain_owner)
 	. = ..()
 	UnregisterSignal(brain_owner)
 	if(!ishuman(brain_owner))

code/game/machinery/dna_infuser/organ_sets/gondola_organs.dm

@@ -33,7 +33,7 @@ Fluoride Stare: After someone says 5 words, blah blah blah...
 	AddElement(/datum/element/organ_set_bonus, /datum/status_effect/organ_set_bonus/gondola)
 	AddElement(/datum/element/noticable_organ, "radiate%PRONOUN_S an aura of serenity.")
 
-/obj/item/organ/internal/heart/gondola/Insert(mob/living/carbon/receiver, special, drop_if_replaced)
+/obj/item/organ/internal/heart/gondola/Insert(mob/living/carbon/receiver, special, movement_flags)
 	. = ..()
 	if(!(FACTION_HOSTILE in receiver.faction))
 		factions_to_remove += FACTION_HOSTILE
@@ -41,7 +41,7 @@ Fluoride Stare: After someone says 5 words, blah blah blah...
 		factions_to_remove += FACTION_MINING
 	receiver.faction |= list(FACTION_HOSTILE, FACTION_MINING)
 
-/obj/item/organ/internal/heart/gondola/Remove(mob/living/carbon/heartless, special)
+/obj/item/organ/internal/heart/gondola/Remove(mob/living/carbon/heartless, special, movement_flags)
 	. = ..()
 	for(var/faction in factions_to_remove)
 		heartless.faction -= faction
@@ -63,11 +63,11 @@ Fluoride Stare: After someone says 5 words, blah blah blah...
 	AddElement(/datum/element/noticable_organ, "mouth is permanently affixed into a relaxed smile.", BODY_ZONE_PRECISE_MOUTH)
 	AddElement(/datum/element/organ_set_bonus, /datum/status_effect/organ_set_bonus/gondola)
 
-/obj/item/organ/internal/tongue/gondola/Insert(mob/living/carbon/tongue_owner, special, drop_if_replaced)
+/obj/item/organ/internal/tongue/gondola/Insert(mob/living/carbon/tongue_owner, special, movement_flags)
 	. = ..()
 	tongue_owner.add_mood_event("gondola_zen", /datum/mood_event/gondola_serenity)
 
-/obj/item/organ/internal/tongue/gondola/Remove(mob/living/carbon/tongue_owner, special)
+/obj/item/organ/internal/tongue/gondola/Remove(mob/living/carbon/tongue_owner, special, movement_flags)
 	tongue_owner.clear_mood_event("gondola_zen")
 	return ..()
 
@@ -89,7 +89,7 @@ Fluoride Stare: After someone says 5 words, blah blah blah...
 	AddElement(/datum/element/noticable_organ, "right arm has small needles breaching the skin all over it.", BODY_ZONE_R_ARM)
 	pax_hugs = new
 
-/obj/item/organ/internal/liver/gondola/Insert(mob/living/carbon/liver_owner, special, drop_if_replaced)
+/obj/item/organ/internal/liver/gondola/Insert(mob/living/carbon/liver_owner, special, movement_flags)
 	. = ..()
 	var/has_left = liver_owner.has_left_hand(check_disabled = FALSE)
 	var/has_right = liver_owner.has_right_hand(check_disabled = FALSE)
@@ -104,7 +104,7 @@ Fluoride Stare: After someone says 5 words, blah blah blah...
 	RegisterSignal(liver_owner, COMSIG_HUMAN_EQUIPPING_ITEM, PROC_REF(on_owner_equipping_item))
 	RegisterSignal(liver_owner, COMSIG_LIVING_TRY_PULL, PROC_REF(on_owner_try_pull))
 
-/obj/item/organ/internal/liver/gondola/Remove(mob/living/carbon/liver_owner, special)
+/obj/item/organ/internal/liver/gondola/Remove(mob/living/carbon/liver_owner, special, movement_flags)
 	. = ..()
 	pax_hugs.remove(liver_owner)
 	UnregisterSignal(liver_owner, list(COMSIG_HUMAN_EQUIPPING_ITEM, COMSIG_LIVING_TRY_PULL))

code/game/machinery/dna_infuser/organ_sets/rat_organs.dm

@@ -63,7 +63,7 @@
 	AddElement(/datum/element/organ_set_bonus, /datum/status_effect/organ_set_bonus/rat)
 	AddElement(/datum/element/noticable_organ, "hunch%PRONOUN_ES over unnaturally!")
 
-/obj/item/organ/internal/heart/rat/on_insert(mob/living/carbon/receiver)
+/obj/item/organ/internal/heart/rat/on_mob_insert(mob/living/carbon/receiver)
 	. = ..()
 	if(!. || !ishuman(receiver))
 		return
@@ -75,7 +75,7 @@
 	if(human_receiver.physiology)
 		human_receiver.physiology.damage_resistance -= 50
 
-/obj/item/organ/internal/heart/rat/on_remove(mob/living/carbon/heartless, special)
+/obj/item/organ/internal/heart/rat/on_mob_remove(mob/living/carbon/heartless, special)
 	. = ..()
 	if(!ishuman(heartless))
 		return
@@ -113,11 +113,11 @@
 	if(message == "hi?")
 		speech_args[SPEECH_MESSAGE] = "Um... cheesed to meet you?"
 
-/obj/item/organ/internal/tongue/rat/on_insert(mob/living/carbon/tongue_owner, special, drop_if_replaced)
+/obj/item/organ/internal/tongue/rat/on_mob_insert(mob/living/carbon/tongue_owner, special, movement_flags)
 	. = ..()
 	RegisterSignal(tongue_owner, COMSIG_CARBON_ITEM_GIVEN, PROC_REF(its_on_the_mouse))
 
-/obj/item/organ/internal/tongue/rat/on_remove(mob/living/carbon/tongue_owner)
+/obj/item/organ/internal/tongue/rat/on_mob_remove(mob/living/carbon/tongue_owner)
 	. = ..()
 	UnregisterSignal(tongue_owner, COMSIG_CARBON_ITEM_GIVEN)
 

code/game/machinery/dna_infuser/organ_sets/roach_organs.dm

@@ -71,7 +71,7 @@
 	QDEL_NULL(roach_shell)
 	return ..()
 
-/obj/item/organ/internal/heart/roach/on_insert(mob/living/carbon/organ_owner, special)
+/obj/item/organ/internal/heart/roach/on_mob_insert(mob/living/carbon/organ_owner, special)
 	. = ..()
 	if(!ishuman(organ_owner))
 		return
@@ -82,11 +82,11 @@
 	RegisterSignal(human_owner, COMSIG_MOB_AFTER_APPLY_DAMAGE, PROC_REF(do_block_effect))
 	human_owner.physiology.knockdown_mod *= 3
 
-	var/obj/item/bodypart/chest/chest = human_owner.get_bodypart(BODY_ZONE_CHEST)
-	chest.add_bodypart_overlay(roach_shell)
-	human_owner.update_body_parts()
+/obj/item/organ/internal/heart/roach/on_bodypart_insert(obj/item/bodypart/limb)
+	. = ..()
+	limb.add_bodypart_overlay(roach_shell)
 
-/obj/item/organ/internal/heart/roach/on_remove(mob/living/carbon/organ_owner, special)
+/obj/item/organ/internal/heart/roach/on_mob_remove(mob/living/carbon/organ_owner, special)
 	. = ..()
 	if(!ishuman(organ_owner) || QDELETED(organ_owner))
 		return
@@ -96,9 +96,10 @@
 	UnregisterSignal(human_owner, list(COMSIG_MOB_APPLY_DAMAGE_MODIFIERS, COMSIG_MOB_AFTER_APPLY_DAMAGE))
 	human_owner.physiology.knockdown_mod /= 3
 
-	var/obj/item/bodypart/chest/chest = human_owner.get_bodypart(BODY_ZONE_CHEST)
-	chest.remove_bodypart_overlay(roach_shell)
-	human_owner.update_body_parts()
+/obj/item/organ/internal/heart/roach/on_bodypart_remove(obj/item/bodypart/limb)
+	. = ..()
+
+	limb.remove_bodypart_overlay(roach_shell)
 
 /**
  * Signal proc for [COMSIG_MOB_APPLY_DAMAGE_MODIFIERS]
@@ -193,7 +194,7 @@
 	. = ..()
 	AddElement(/datum/element/organ_set_bonus, /datum/status_effect/organ_set_bonus/roach)
 
-/obj/item/organ/internal/liver/roach/on_insert(mob/living/carbon/organ_owner, special)
+/obj/item/organ/internal/liver/roach/on_mob_insert(mob/living/carbon/organ_owner, special)
 	. = ..()
 	if(!ishuman(organ_owner))
 		return
@@ -201,13 +202,13 @@
 	var/mob/living/carbon/human/human_owner = owner
 	human_owner.physiology.tox_mod *= 2
 
-/obj/item/organ/internal/liver/roach/on_remove(mob/living/carbon/organ_owner, special)
+/obj/item/organ/internal/liver/roach/on_mob_remove(mob/living/carbon/organ_owner, special)
 	. = ..()
 	if(!ishuman(organ_owner) || QDELETED(organ_owner))
 		return
 
 	var/mob/living/carbon/human/human_owner = organ_owner
-	human_owner.physiology.tox_mod /= 2
+	human_owner.physiology.tox_mod *= 0.5
 
 /// Roach appendix:
 /// No appendicitus! weee!

code/game/machinery/recycler.dm

@@ -151,6 +151,10 @@
 			var/obj/item/mmi/as_mmi = thing
 			if(istype(thing, /obj/item/organ/internal/brain) || (istype(as_head) && as_head.brain) || (istype(as_mmi) && as_mmi.brain) || istype(thing, /obj/item/dullahan_relay))
 				living_detected = TRUE
+			if(isitem(as_object))
+				var/obj/item/as_item = as_object
+				if(as_item.item_flags & ABSTRACT) //also catches organs and bodyparts *stares*
+					continue
 			nom += thing
 		else if(isliving(thing))
 			living_detected = TRUE

code/game/objects/items/body_egg.dm

@@ -15,7 +15,7 @@
 	if(iscarbon(loc))
 		Insert(loc)
 
-/obj/item/organ/internal/body_egg/Insert(mob/living/carbon/egg_owner, special = FALSE, drop_if_replaced = TRUE)
+/obj/item/organ/internal/body_egg/Insert(mob/living/carbon/egg_owner, special = FALSE, movement_flags = DELETE_IF_REPLACED)
 	. = ..()
 	if(!.)
 		return
@@ -23,7 +23,7 @@
 	egg_owner.med_hud_set_status()
 	INVOKE_ASYNC(src, PROC_REF(AddInfectionImages), egg_owner)
 
-/obj/item/organ/internal/body_egg/Remove(mob/living/carbon/egg_owner, special = FALSE)
+/obj/item/organ/internal/body_egg/Remove(mob/living/carbon/egg_owner, special, movement_flags)
 	. = ..()
 	egg_owner.remove_traits(list(TRAIT_XENO_HOST, TRAIT_XENO_IMMUNE), ORGAN_TRAIT)
 	egg_owner.med_hud_set_status()

code/game/turfs/open/lava.dm

@@ -418,7 +418,7 @@
 			if(BODY_ZONE_HEAD)
 				plasmalimb = new /obj/item/bodypart/head/plasmaman
 
-		burn_human.del_and_replace_bodypart(plasmalimb)
+		burn_human.del_and_replace_bodypart(plasmalimb, special = TRUE)
 		burn_human.update_body_parts()
 		burn_human.emote("scream")
 		burn_human.visible_message(span_warning("[burn_human]'s [burn_limb.plaintext_zone] melts down to the bone!"), \

code/modules/admin/verbs/admin.dm

@@ -176,6 +176,10 @@
 
 	for(var/obj/item/W in M)
 		if(!M.dropItemToGround(W))
+			// I hate that this is necessary, but the code is literally just dropping or deleting everything otherwise
+			// people should be allowed to keep their fucking organs
+			if(istype(W, /obj/item/organ) || istype(W, /obj/item/bodypart))
+				continue
 			qdel(W)
 			M.regenerate_icons()
 

code/modules/admin/verbs/secrets.dm

@@ -506,8 +506,8 @@ GLOBAL_DATUM(everyone_a_traitor, /datum/everyone_is_a_traitor_controller)
 					if(H.dna.features["tail_human"] == "None" || H.dna.features["ears"] == "None")
 						var/obj/item/organ/internal/ears/cat/ears = new
 						var/obj/item/organ/external/tail/cat/tail = new
-						ears.Insert(H, drop_if_replaced=FALSE)
-						tail.Insert(H, drop_if_replaced=FALSE)
+						ears.Insert(H, movement_flags = DELETE_IF_REPLACED)
+						tail.Insert(H, movement_flags = DELETE_IF_REPLACED)
 					var/list/honorifics = list("[MALE]" = list("kun"), "[FEMALE]" = list("chan","tan"), "[NEUTER]" = list("san"), "[PLURAL]" = list("san")) //John Robust -> Robust-kun
 					var/list/names = splittext(H.real_name," ")
 					var/forename = names.len > 1 ? names[2] : names[1]

code/modules/antagonists/abductor/equipment/gland.dm

@@ -84,7 +84,7 @@
 	active_mind_control = FALSE
 	return TRUE
 
-/obj/item/organ/internal/heart/gland/Remove(mob/living/carbon/gland_owner, special = FALSE)
+/obj/item/organ/internal/heart/gland/Remove(mob/living/carbon/gland_owner, special, movement_flags)
 	. = ..()
 	active = FALSE
 	if(initial(uses) == 1)
@@ -93,7 +93,7 @@
 	hud.remove_atom_from_hud(gland_owner)
 	clear_mind_control()
 
-/obj/item/organ/internal/heart/gland/Insert(mob/living/carbon/gland_owner, special = FALSE, drop_if_replaced = TRUE)
+/obj/item/organ/internal/heart/gland/Insert(mob/living/carbon/gland_owner, special = FALSE, movement_flags = DELETE_IF_REPLACED)
 	. = ..()
 	if(!.)
 		return

code/modules/antagonists/abductor/equipment/glands/electric.dm

@@ -7,11 +7,11 @@
 	mind_control_uses = 2
 	mind_control_duration = 900
 
-/obj/item/organ/internal/heart/gland/electric/on_insert(mob/living/carbon/gland_owner)
+/obj/item/organ/internal/heart/gland/electric/on_mob_insert(mob/living/carbon/gland_owner)
 	. = ..()
 	ADD_TRAIT(gland_owner, TRAIT_SHOCKIMMUNE, ABDUCTOR_GLAND_TRAIT)
 
-/obj/item/organ/internal/heart/gland/electric/on_remove(mob/living/carbon/gland_owner)
+/obj/item/organ/internal/heart/gland/electric/on_mob_remove(mob/living/carbon/gland_owner)
 	. = ..()
 	REMOVE_TRAIT(gland_owner, TRAIT_SHOCKIMMUNE, ABDUCTOR_GLAND_TRAIT)
 

code/modules/antagonists/abductor/equipment/glands/slime.dm

@@ -7,12 +7,12 @@
 	mind_control_uses = 1
 	mind_control_duration = 2400
 
-/obj/item/organ/internal/heart/gland/slime/on_insert(mob/living/carbon/gland_owner)
+/obj/item/organ/internal/heart/gland/slime/on_mob_insert(mob/living/carbon/gland_owner)
 	. = ..()
 	gland_owner.faction |= FACTION_SLIME
 	gland_owner.grant_language(/datum/language/slime, source = LANGUAGE_GLAND)
 
-/obj/item/organ/internal/heart/gland/slime/on_remove(mob/living/carbon/gland_owner)
+/obj/item/organ/internal/heart/gland/slime/on_mob_remove(mob/living/carbon/gland_owner)
 	. = ..()
 	gland_owner.faction -= FACTION_SLIME
 	gland_owner.remove_language(/datum/language/slime, source = LANGUAGE_GLAND)

code/modules/antagonists/fugitive/fugitive_outfits.dm

@@ -67,7 +67,7 @@
 	if(visualsOnly)
 		return
 	var/obj/item/organ/internal/eyes/robotic/glow/eyes = new()
-	eyes.Insert(H, drop_if_replaced = FALSE)
+	eyes.Insert(H, movement_flags = DELETE_IF_REPLACED)
 
 /datum/outfit/invisible_man
 	name = "Invisible Man"

code/modules/antagonists/heretic/knowledge/lock_lore.dm

@@ -199,8 +199,7 @@
 	for(var/mob/living/carbon/human/body in atoms)
 		if(body.stat != DEAD)
 			continue
-		var/obj/item/bodypart/chest = body.get_bodypart(BODY_ZONE_CHEST)
-		if(LAZYLEN(chest.get_organs()))
+		if(LAZYLEN(body.get_organs_for_zone(BODY_ZONE_CHEST)))
 			to_chat(user, span_hierophant_warning("[body] has organs in their chest."))
 			continue
 

code/modules/antagonists/heretic/transmutation_rune.dm

@@ -80,6 +80,10 @@
 	for(var/atom/close_atom as anything in range(1, src))
 		if(!ismovable(close_atom))
 			continue
+		if(isitem(close_atom))
+			var/obj/item/close_item = close_atom
+			if(close_item.item_flags & ABSTRACT) //woops sacrificed your own head
+				continue
 		if(close_atom.invisibility)
 			continue
 		if(close_atom == user)

code/modules/antagonists/nightmare/nightmare_organs.dm

@@ -14,8 +14,10 @@
 	///Our associated terrorize spell, for antagonist nightmares
 	var/datum/action/cooldown/spell/pointed/terrorize/terrorize_spell
 
-/obj/item/organ/internal/brain/shadow/nightmare/on_insert(mob/living/carbon/brain_owner)
+/obj/item/organ/internal/brain/shadow/nightmare/on_mob_insert(mob/living/carbon/brain_owner)
 	. = ..()
+	RegisterSignal(brain_owner, COMSIG_ATOM_PRE_BULLET_ACT, PROC_REF(dodge_bullets))
+
 	if(brain_owner.dna.species.id != SPECIES_NIGHTMARE)
 		brain_owner.set_species(/datum/species/shadow/nightmare)
 		visible_message(span_warning("[brain_owner] thrashes as [src] takes root in [brain_owner.p_their()] body!"))
@@ -27,9 +29,7 @@
 		terrorize_spell = new(src)
 		terrorize_spell.Grant(brain_owner)
 
-	RegisterSignal(brain_owner, COMSIG_ATOM_PRE_BULLET_ACT, PROC_REF(dodge_bullets))
-
-/obj/item/organ/internal/brain/shadow/nightmare/on_remove(mob/living/carbon/brain_owner)
+/obj/item/organ/internal/brain/shadow/nightmare/on_mob_remove(mob/living/carbon/brain_owner)
 	. = ..()
 	QDEL_NULL(our_jaunt)
 	QDEL_NULL(terrorize_spell)
@@ -76,13 +76,13 @@
 	user.temporarilyRemoveItemFromInventory(src, TRUE)
 	Insert(user)
 
-/obj/item/organ/internal/heart/nightmare/on_insert(mob/living/carbon/heart_owner, special)
+/obj/item/organ/internal/heart/nightmare/on_mob_insert(mob/living/carbon/heart_owner, special)
 	. = ..()
 	if(special != HEART_SPECIAL_SHADOWIFY)
 		blade = new/obj/item/light_eater
 		heart_owner.put_in_hands(blade)
 
-/obj/item/organ/internal/heart/nightmare/on_remove(mob/living/carbon/heart_owner, special)
+/obj/item/organ/internal/heart/nightmare/on_mob_remove(mob/living/carbon/heart_owner, special)
 	. = ..()
 	respawn_progress = 0
 	if(blade && special != HEART_SPECIAL_SHADOWIFY)

code/modules/jobs/job_types/chaplain/chaplain_vorpal_scythe.dm

@@ -10,7 +10,7 @@ If the scythe isn't empowered when you sheath it, you take a heap of damage and
 	desc = "This shard seems to be directly linked to some sinister entity. It might be your god! It also gives you a really horrible rash when you hold onto it for too long."
 	items_to_create = list(/obj/item/vorpalscythe)
 
-/obj/item/organ/internal/cyberimp/arm/shard/scythe/Insert(mob/living/carbon/receiver, special, drop_if_replaced)
+/obj/item/organ/internal/cyberimp/arm/shard/scythe/Insert(mob/living/carbon/receiver, special, movement_flags)
 	. = ..()
 	if(receiver.mind)
 		ADD_TRAIT(receiver.mind, TRAIT_MORBID, ORGAN_TRAIT)

code/modules/library/skill_learning/skillchip.dm

@@ -106,7 +106,7 @@
 		return "Skillchip is not active."
 
 	// Should not happen. Holding brain is destroyed and the chip hasn't had its state set appropriately.
-	if(QDELETED(holding_brain))
+	if(!holding_brain)
 		stack_trace("Skillchip's owner is null or qdeleted brain.")
 		return "Skillchip cannot detect viable brain."
 

code/modules/mining/equipment/monster_organs/monster_organ.dm

@@ -69,7 +69,7 @@
 	deltimer(decay_timer)
 	return ..()
 
-/obj/item/organ/internal/monster_core/Insert(mob/living/carbon/target_carbon, special = FALSE, drop_if_replaced = TRUE)
+/obj/item/organ/internal/monster_core/Insert(mob/living/carbon/target_carbon, special = FALSE, movement_flags)
 	. = ..()
 	if(!.)
 		return
@@ -83,7 +83,7 @@
 	target_carbon.visible_message(span_notice("[src] stabilizes as it's inserted."))
 	return TRUE
 
-/obj/item/organ/internal/monster_core/Remove(mob/living/carbon/target_carbon, special = 0)
+/obj/item/organ/internal/monster_core/Remove(mob/living/carbon/target_carbon, special, movement_flags)
 	if (!inert && !special)
 		owner.visible_message(span_notice("[src] rapidly decays as it's removed."))
 		go_inert()

code/modules/mining/equipment/monster_organs/rush_gland.dm

@@ -21,11 +21,11 @@
 	if (owner.health <= HEALTH_DANGER_ZONE)
 		trigger_organ_action()
 
-/obj/item/organ/internal/monster_core/rush_gland/on_insert(mob/living/carbon/organ_owner)
+/obj/item/organ/internal/monster_core/rush_gland/on_mob_insert(mob/living/carbon/organ_owner)
 	. = ..()
 	RegisterSignal(organ_owner, COMSIG_GOLIATH_TENTACLED_GRABBED, PROC_REF(trigger_organ_action))
 
-/obj/item/organ/internal/monster_core/rush_gland/on_remove(mob/living/carbon/organ_owner, special)
+/obj/item/organ/internal/monster_core/rush_gland/on_mob_remove(mob/living/carbon/organ_owner, special)
 	. = ..()
 	UnregisterSignal(organ_owner, COMSIG_GOLIATH_TENTACLED_GRABBED)
 

code/modules/mob/living/basic/lavaland/legion/legion.dm

@@ -83,7 +83,7 @@
 		return
 	// Congratulations you have won a special prize: cancer
 	var/obj/item/organ/internal/legion_tumour/cancer = new()
-	cancer.Insert(consumed, special = TRUE, drop_if_replaced = FALSE)
+	cancer.Insert(consumed, special = TRUE, movement_flags = DELETE_IF_REPLACED)
 
 /// A Legion which only drops skeletons instead of corpses which might have fun loot, so it cannot be farmed
 

code/modules/mob/living/basic/lavaland/legion/legion_tumour.dm

@@ -50,7 +50,7 @@
 	animate(transform = matrix(), time = 0.5 SECONDS / speed_divider, easing = SINE_EASING | EASE_IN)
 	animate(transform = matrix(), time = 2 SECONDS / speed_divider)
 
-/obj/item/organ/internal/legion_tumour/Remove(mob/living/carbon/egg_owner, special)
+/obj/item/organ/internal/legion_tumour/Remove(mob/living/carbon/egg_owner, special, movement_flags)
 	. = ..()
 	stage = 0
 	elapsed_time = 0

code/modules/mob/living/basic/space_fauna/demon/demon_items.dm

@@ -33,13 +33,13 @@
 	user.temporarilyRemoveItemFromInventory(src, TRUE)
 	src.Insert(user) //Consuming the heart literally replaces your heart with a demon heart. H A R D C O R E
 
-/obj/item/organ/internal/heart/demon/on_insert(mob/living/carbon/heart_owner)
+/obj/item/organ/internal/heart/demon/on_mob_insert(mob/living/carbon/heart_owner)
 	. = ..()
 	// Gives a non-eat-people crawl to the new owner
 	var/datum/action/cooldown/spell/jaunt/bloodcrawl/crawl = new(heart_owner)
 	crawl.Grant(heart_owner)
 
-/obj/item/organ/internal/heart/demon/on_remove(mob/living/carbon/heart_owner, special = FALSE)
+/obj/item/organ/internal/heart/demon/on_mob_remove(mob/living/carbon/heart_owner, special = FALSE)
 	. = ..()
 	var/datum/action/cooldown/spell/jaunt/bloodcrawl/crawl = locate() in heart_owner.actions
 	qdel(crawl)

code/modules/mob/living/blood.dm

@@ -286,7 +286,7 @@
 		return /datum/reagent/blood
 
 /mob/living/carbon/human/get_blood_id()
-	if(HAS_TRAIT(src, TRAIT_HUSK))
+	if(HAS_TRAIT(src, TRAIT_HUSK) || !dna)
 		return
 	if(check_holidays(APRIL_FOOLS) && is_clown_job(mind?.assigned_role))
 		return /datum/reagent/colorful_reagent

code/modules/mob/living/brain/brain_item.dm

@@ -47,7 +47,14 @@
 	// Brain size logic
 	transform = transform.Scale(brain_size)
 
-/obj/item/organ/internal/brain/Insert(mob/living/carbon/brain_owner, special = FALSE, drop_if_replaced = TRUE, no_id_transfer = FALSE)
+/obj/item/organ/internal/brain/examine()
+	. = ..()
+	if(brain_size < 1)
+		. += span_notice("It is a bit on the smaller side...")
+	if(brain_size > 1)
+		. += span_notice("It is bigger than average...")
+
+/obj/item/organ/internal/brain/mob_insert(mob/living/carbon/brain_owner, special = FALSE, movement_flags)
 	. = ..()
 	if(!.)
 		return
@@ -55,7 +62,7 @@
 	name = initial(name)
 
 	// Special check for if you're trapped in a body you can't control because it's owned by a ling.
-	if(brain_owner?.mind?.has_antag_datum(/datum/antagonist/changeling) && !no_id_transfer)
+	if(brain_owner?.mind?.has_antag_datum(/datum/antagonist/changeling) && !(movement_flags & NO_ID_TRANSFER))
 		if(brainmob && !(brain_owner.stat == DEAD || (HAS_TRAIT(brain_owner, TRAIT_DEATHCOMA))))
 			to_chat(brainmob, span_danger("You can't feel your body! You're still just a brain!"))
 		forceMove(brain_owner)
@@ -102,25 +109,11 @@
 	//Update the body's icon so it doesnt appear debrained anymore
 	brain_owner.update_body_parts()
 
-/obj/item/organ/internal/brain/on_insert(mob/living/carbon/organ_owner, special)
-	// Are we inserting into a new mob from a head?
-	// If yes, we want to quickly steal the brainmob from the head before we do anything else.
-	// This is usually stuff like reattaching dismembered/amputated heads.
-	if(istype(loc, /obj/item/bodypart/head))
-		var/obj/item/bodypart/head/brain_holder = loc
-		if(brain_holder.brainmob)
-			brainmob = brain_holder.brainmob
-			brain_holder.brainmob = null
-			brainmob.container = null
-			brainmob.forceMove(src)
-
-	return ..()
-
-/obj/item/organ/internal/brain/Remove(mob/living/carbon/brain_owner, special = 0, no_id_transfer = FALSE)
+/obj/item/organ/internal/brain/mob_remove(mob/living/carbon/organ_owner, special, movement_flags)
 	// Delete skillchips first as parent proc sets owner to null, and skillchips need to know the brain's owner.
-	if(!QDELETED(brain_owner) && length(skillchips))
+	if(!QDELETED(organ_owner) && length(skillchips))
 		if(!special)
-			to_chat(brain_owner, span_notice("You feel your skillchips enable emergency power saving mode, deactivating as your brain leaves your body..."))
+			to_chat(organ_owner, span_notice("You feel your skillchips enable emergency power saving mode, deactivating as your brain leaves your body..."))
 		for(var/chip in skillchips)
 			var/obj/item/skillchip/skillchip = chip
 			// Run the try_ proc with force = TRUE.
@@ -133,10 +126,11 @@
 		BT.on_lose(TRUE)
 		BT.owner = null
 
-	if((!gc_destroyed || (owner && !owner.gc_destroyed)) && !no_id_transfer)
-		transfer_identity(brain_owner)
-	brain_owner.update_body_parts()
-	brain_owner.clear_mood_event("brain_damage")
+	if((!gc_destroyed || (owner && !owner.gc_destroyed)) && !(movement_flags & NO_ID_TRANSFER))
+		transfer_identity(organ_owner)
+	if(!special)
+		organ_owner.update_body_parts()
+		organ_owner.clear_mood_event("brain_damage")
 
 /obj/item/organ/internal/brain/proc/transfer_identity(mob/living/L)
 	name = "[L.name]'s [initial(name)]"
@@ -417,11 +411,11 @@
 	icon_state = "random_fly_4"
 	organ_traits = list(TRAIT_ADVANCEDTOOLUSER, TRAIT_LITERATE, TRAIT_CAN_STRIP)
 
-/obj/item/organ/internal/brain/lustrous/before_organ_replacement(mob/living/carbon/organ_owner, special)
+/obj/item/organ/internal/brain/lustrous/on_mob_remove(mob/living/carbon/organ_owner, special)
 	. = ..()
 	organ_owner.cure_trauma_type(/datum/brain_trauma/special/bluespace_prophet, TRAUMA_RESILIENCE_ABSOLUTE)
 
-/obj/item/organ/internal/brain/lustrous/on_insert(mob/living/carbon/organ_owner, special)
+/obj/item/organ/internal/brain/lustrous/on_mob_insert(mob/living/carbon/organ_owner, special)
 	. = ..()
 	organ_owner.gain_trauma(/datum/brain_trauma/special/bluespace_prophet, TRAUMA_RESILIENCE_ABSOLUTE)
 
@@ -580,6 +574,6 @@
 /// Brains REALLY like ghosting people. we need special tricks to avoid that, namely removing the old brain with no_id_transfer
 /obj/item/organ/internal/brain/replace_into(mob/living/carbon/new_owner)
 	var/obj/item/organ/internal/brain/old_brain = new_owner.get_organ_slot(ORGAN_SLOT_BRAIN)
-	old_brain.Remove(new_owner, special = TRUE, no_id_transfer = TRUE)
+	old_brain.Remove(new_owner, special = TRUE, movement_flags = NO_ID_TRANSFER)
 	qdel(old_brain)
-	return Insert(new_owner, special = TRUE, drop_if_replaced = FALSE, no_id_transfer = TRUE)
+	return Insert(new_owner, special = TRUE, movement_flags = NO_ID_TRANSFER | DELETE_IF_REPLACED)

code/modules/mob/living/carbon/alien/organs.dm

@@ -69,14 +69,14 @@
 	else
 		owner.adjustPlasma(0.1 * plasma_rate * delta_time)
 
-/obj/item/organ/internal/alien/plasmavessel/on_insert(mob/living/carbon/organ_owner)
+/obj/item/organ/internal/alien/plasmavessel/on_mob_insert(mob/living/carbon/organ_owner)
 	. = ..()
 	if(isalien(organ_owner))
 		var/mob/living/carbon/alien/target_alien = organ_owner
 		target_alien.updatePlasmaDisplay()
 	RegisterSignal(organ_owner, COMSIG_MOB_GET_STATUS_TAB_ITEMS, PROC_REF(get_status_tab_item))
 
-/obj/item/organ/internal/alien/plasmavessel/on_remove(mob/living/carbon/organ_owner)
+/obj/item/organ/internal/alien/plasmavessel/on_mob_remove(mob/living/carbon/organ_owner)
 	. = ..()
 	if(isalien(organ_owner))
 		var/mob/living/carbon/alien/organ_owner_alien = organ_owner
@@ -95,18 +95,18 @@
 	zone = BODY_ZONE_HEAD
 	slot = ORGAN_SLOT_XENO_HIVENODE
 	w_class = WEIGHT_CLASS_TINY
+	organ_traits = list(TRAIT_XENO_IMMUNE)
 	actions_types = list(/datum/action/cooldown/alien/whisper)
 	/// Indicates if the queen died recently, aliens are heavily weakened while this is active.
 	var/recent_queen_death = FALSE
 
-/obj/item/organ/internal/alien/hivenode/on_insert(mob/living/carbon/organ_owner)
+/obj/item/organ/internal/alien/hivenode/on_mob_insert(mob/living/carbon/organ_owner)
 	. = ..()
 	organ_owner.faction |= ROLE_ALIEN
-	ADD_TRAIT(organ_owner, TRAIT_XENO_IMMUNE, ORGAN_TRAIT)
 
-/obj/item/organ/internal/alien/hivenode/Remove(mob/living/carbon/organ_owner, special = FALSE)
-	organ_owner.faction -= ROLE_ALIEN
-	REMOVE_TRAIT(organ_owner, TRAIT_XENO_IMMUNE, ORGAN_TRAIT)
+/obj/item/organ/internal/alien/hivenode/on_mob_remove(mob/living/carbon/organ_owner, special = FALSE)
+	if(organ_owner)
+		organ_owner.faction -= ROLE_ALIEN
 	return ..()
 
 //When the alien queen dies, all aliens suffer a penalty as punishment for failing to protect her.
@@ -232,11 +232,11 @@
 	stomach_contents -= source
 	UnregisterSignal(source, list(COMSIG_MOVABLE_MOVED, COMSIG_LIVING_DEATH, COMSIG_QDELETING))
 
-/obj/item/organ/internal/stomach/alien/Insert(mob/living/carbon/stomach_owner, special = FALSE, drop_if_replaced = TRUE)
+/obj/item/organ/internal/stomach/alien/Insert(mob/living/carbon/stomach_owner, special, movement_flags)
 	RegisterSignal(stomach_owner, COMSIG_ATOM_RELAYMOVE, PROC_REF(something_moved))
 	return ..()
 
-/obj/item/organ/internal/stomach/alien/Remove(mob/living/carbon/stomach_owner, special = FALSE)
+/obj/item/organ/internal/stomach/alien/Remove(mob/living/carbon/stomach_owner, special, movement_flags)
 	UnregisterSignal(stomach_owner, COMSIG_ATOM_RELAYMOVE)
 	return ..()
 

code/modules/mob/living/carbon/carbon.dm

@@ -979,7 +979,6 @@
 	for(var/obj/item/bodypart/bodypart_path as anything in bodyparts_paths)
 		var/real_body_part_path = overrides?[initial(bodypart_path.body_zone)] || bodypart_path
 		var/obj/item/bodypart/bodypart_instance = new real_body_part_path()
-		bodypart_instance.set_owner(src)
 		add_bodypart(bodypart_instance)
 
 /// Called when a new hand is added
@@ -996,8 +995,12 @@
 /mob/living/carbon/proc/add_bodypart(obj/item/bodypart/new_bodypart)
 	SHOULD_NOT_OVERRIDE(TRUE)
 
+	new_bodypart.on_adding(src)
 	bodyparts += new_bodypart
-	new_bodypart.set_owner(src)
+	new_bodypart.update_owner(src)
+
+	for(var/obj/item/organ/organ in new_bodypart)
+		organ.mob_insert(src)
 
 	switch(new_bodypart.body_part)
 		if(LEG_LEFT, LEG_RIGHT)
@@ -1012,10 +1015,17 @@
 	synchronize_bodytypes()
 
 ///Proc to hook behavior on bodypart removals.  Do not directly call. You're looking for [/obj/item/bodypart/proc/drop_limb()].
-/mob/living/carbon/proc/remove_bodypart(obj/item/bodypart/old_bodypart)
+/mob/living/carbon/proc/remove_bodypart(obj/item/bodypart/old_bodypart, special)
 	SHOULD_NOT_OVERRIDE(TRUE)
 
-	old_bodypart.on_removal()
+	if(special)
+		for(var/obj/item/organ/organ in old_bodypart)
+			organ.bodypart_remove(limb_owner = src, movement_flags = NO_ID_TRANSFER)
+	else
+		for(var/obj/item/organ/organ in old_bodypart)
+			organ.mob_remove(src, special)
+
+	old_bodypart.on_removal(src)
 	bodyparts -= old_bodypart
 
 	switch(old_bodypart.body_part)
@@ -1413,3 +1423,8 @@
 	our_splatter.blood_dna_info = get_blood_dna_list()
 	var/turf/targ = get_ranged_target_turf(src, splatter_direction, splatter_strength)
 	our_splatter.fly_towards(targ, splatter_strength)
+
+/mob/living/carbon/dropItemToGround(obj/item/item, force = FALSE, silent = FALSE, invdrop = TRUE)
+	if(item && ((item in organs) || (item in bodyparts))) //let's not do this, aight?
+		return FALSE
+	return ..()

code/modules/mob/living/carbon/death.dm

@@ -28,9 +28,9 @@
 	add_memory_in_range(src, 7, /datum/memory/witness_gib, protagonist = src)
 	if(drop_bitflags & DROP_ITEMS)
 		for(var/obj/item/W in src)
-			dropItemToGround(W)
-			if(prob(50))
-				step(W, pick(GLOB.alldirs))
+			if(dropItemToGround(W))
+				if(prob(50))
+					step(W, pick(GLOB.alldirs))
 	var/atom/Tsec = drop_location()
 	for(var/mob/M in src)
 		M.forceMove(Tsec)

code/modules/mob/living/carbon/human/_species.dm

@@ -370,19 +370,17 @@ GLOBAL_LIST_EMPTY(features_by_species)
 			health_pct = (existing_organ.maxHealth - existing_organ.damage) / existing_organ.maxHealth
 			if(slot == ORGAN_SLOT_BRAIN)
 				var/obj/item/organ/internal/brain/existing_brain = existing_organ
-				if(!existing_brain.decoy_override)
-					existing_brain.before_organ_replacement(new_organ)
-					existing_brain.Remove(organ_holder, special = TRUE, no_id_transfer = TRUE)
-					QDEL_NULL(existing_organ)
+				existing_brain.before_organ_replacement(new_organ)
+				existing_brain.Remove(organ_holder, special = TRUE, movement_flags = NO_ID_TRANSFER)
 			else
 				existing_organ.before_organ_replacement(new_organ)
 				existing_organ.Remove(organ_holder, special = TRUE)
-				QDEL_NULL(existing_organ)
 
-		if(isnull(existing_organ) && should_have && !(new_organ.zone in excluded_zones))
+			QDEL_NULL(existing_organ)
+		if(isnull(existing_organ) && should_have && !(new_organ.zone in excluded_zones) && organ_holder.get_bodypart(deprecise_zone(new_organ.zone)))
 			used_neworgan = TRUE
 			new_organ.set_organ_damage(new_organ.maxHealth * (1 - health_pct))
-			new_organ.Insert(organ_holder, special = TRUE, drop_if_replaced = FALSE)
+			new_organ.Insert(organ_holder, special = TRUE, movement_flags = DELETE_IF_REPLACED)
 
 		if(!used_neworgan)
 			QDEL_NULL(new_organ)
@@ -425,7 +423,7 @@ GLOBAL_LIST_EMPTY(features_by_species)
 			if(current_organ)
 				current_organ.before_organ_replacement(replacement)
 			// organ.Insert will qdel any current organs in that slot, so we don't need to.
-			replacement.Insert(organ_holder, special=TRUE, drop_if_replaced=FALSE)
+			replacement.Insert(organ_holder, special=TRUE, movement_flags = DELETE_IF_REPLACED)
 
 /datum/species/proc/worn_items_fit_body_check(mob/living/carbon/wearer)
 	for(var/obj/item/equipped_item in wearer.get_all_worn_items())
@@ -492,7 +490,7 @@ GLOBAL_LIST_EMPTY(features_by_species)
 
 			//Load a persons preferences from DNA
 			var/obj/item/organ/external/new_organ = SSwardrobe.provide_type(organ_path)
-			new_organ.Insert(human, special=TRUE, drop_if_replaced=FALSE)
+			new_organ.Insert(human, special=TRUE, movement_flags = DELETE_IF_REPLACED)
 
 
 

code/modules/mob/living/carbon/human/human_defines.dm

@@ -13,6 +13,7 @@
 	mob_biotypes = MOB_ORGANIC|MOB_HUMANOID
 	can_be_shoved_into = TRUE
 	initial_language_holder = /datum/language_holder/empty // We get stuff from our species
+	flags_1 = PREVENT_CONTENTS_EXPLOSION_1
 
 	//Hair colour and style
 	var/hair_color = "#000000"

code/modules/mob/living/carbon/human/species_types/felinid.dm

@@ -41,7 +41,7 @@
 				target_human.dna.features["ears"] = "Cat"
 		if(target_human.dna.features["ears"] == "Cat")
 			var/obj/item/organ/internal/ears/cat/ears = new
-			ears.Insert(target_human, drop_if_replaced = FALSE)
+			ears.Insert(target_human, movement_flags = DELETE_IF_REPLACED)
 		else
 			mutantears = /obj/item/organ/internal/ears
 	return ..()
@@ -92,8 +92,8 @@
 		// Humans get converted directly to felinids, and the key is handled in on_species_gain.
 		// Now when we get mob.dna.features[feature_key], it returns None, which is why the tail is invisible.
 		// stored_feature_id is only set once (the first time an organ is inserted), so this should be safe.
-		kitty_ears.Insert(soon_to_be_felinid, special = TRUE, drop_if_replaced = FALSE)
-		kitty_tail.Insert(soon_to_be_felinid, special = TRUE, drop_if_replaced = FALSE)
+		kitty_ears.Insert(soon_to_be_felinid, special = TRUE, movement_flags = DELETE_IF_REPLACED)
+		kitty_tail.Insert(soon_to_be_felinid, special = TRUE, movement_flags = DELETE_IF_REPLACED)
 	if(!silent)
 		to_chat(soon_to_be_felinid, span_boldnotice("Something is nya~t right."))
 		playsound(get_turf(soon_to_be_felinid), 'sound/effects/meow1.ogg', 50, TRUE, -1)
@@ -116,16 +116,16 @@
 			for(var/external_organ in target_species.external_organs)
 				if(ispath(external_organ, /obj/item/organ/external/tail))
 					var/obj/item/organ/external/tail/new_tail = new external_organ()
-					new_tail.Insert(purrbated_human, special = TRUE, drop_if_replaced = FALSE)
+					new_tail.Insert(purrbated_human, special = TRUE, movement_flags = DELETE_IF_REPLACED)
 				// Don't forget the spines we removed earlier
 				else if(ispath(external_organ, /obj/item/organ/external/spines))
 					var/obj/item/organ/external/spines/new_spines = new external_organ()
-					new_spines.Insert(purrbated_human, special = TRUE, drop_if_replaced = FALSE)
+					new_spines.Insert(purrbated_human, special = TRUE, movement_flags = DELETE_IF_REPLACED)
 
 		var/obj/item/organ/internal/ears/old_ears = purrbated_human.get_organ_slot(ORGAN_SLOT_EARS)
 		if(istype(old_ears, /obj/item/organ/internal/ears/cat))
 			var/obj/item/organ/new_ears = new target_species.mutantears()
-			new_ears.Insert(purrbated_human, special = TRUE, drop_if_replaced = FALSE)
+			new_ears.Insert(purrbated_human, special = TRUE, movement_flags = DELETE_IF_REPLACED)
 	if(!silent)
 		to_chat(purrbated_human, span_boldnotice("You are no longer a cat."))
 

code/modules/mob/living/carbon/human/species_types/monkeys.dm

@@ -166,11 +166,11 @@
 	build_all_button_icons()
 
 
-/obj/item/organ/internal/brain/primate/on_insert(mob/living/carbon/primate)
+/obj/item/organ/internal/brain/primate/on_mob_insert(mob/living/carbon/primate)
 	. = ..()
 	RegisterSignal(primate, COMSIG_MOVABLE_CROSS, PROC_REF(on_crossed), TRUE)
 
-/obj/item/organ/internal/brain/primate/on_remove(mob/living/carbon/primate)
+/obj/item/organ/internal/brain/primate/on_mob_remove(mob/living/carbon/primate)
 	. = ..()
 	UnregisterSignal(primate, COMSIG_MOVABLE_CROSS)
 

code/modules/mob/living/carbon/human/species_types/vampire.dm

@@ -203,11 +203,11 @@
 	name = "vampire heart"
 	color = "#1C1C1C"
 
-/obj/item/organ/internal/heart/vampire/on_insert(mob/living/carbon/receiver)
+/obj/item/organ/internal/heart/vampire/on_mob_insert(mob/living/carbon/receiver)
 	. = ..()
 	RegisterSignal(receiver, COMSIG_MOB_GET_STATUS_TAB_ITEMS, PROC_REF(get_status_tab_item))
 
-/obj/item/organ/internal/heart/vampire/on_remove(mob/living/carbon/heartless)
+/obj/item/organ/internal/heart/vampire/on_mob_remove(mob/living/carbon/heartless)
 	. = ..()
 	UnregisterSignal(heartless, COMSIG_MOB_GET_STATUS_TAB_ITEMS)
 

code/modules/mob/living/living.dm

@@ -1391,7 +1391,7 @@
 		Robot.notify_ai(AI_NOTIFICATION_NEW_BORG)
 	else
 		for(var/obj/item/item in src)
-			if(!dropItemToGround(item))
+			if(!dropItemToGround(item) && !(item.item_flags & ABSTRACT))
 				qdel(item)
 				continue
 			item_contents += item

code/modules/mob_spawn/corpses/mining_corpses.dm

@@ -27,7 +27,7 @@
 /obj/effect/mob_spawn/corpse/human/legioninfested/special(mob/living/carbon/human/spawned_human)
 	. = ..()
 	var/obj/item/organ/internal/legion_tumour/cancer = new()
-	cancer.Insert(spawned_human, special = TRUE, drop_if_replaced = FALSE)
+	cancer.Insert(spawned_human, special = TRUE, movement_flags = DELETE_IF_REPLACED)
 
 /// Returns the outfit worn by our corpse
 /obj/effect/mob_spawn/corpse/human/legioninfested/proc/select_outfit()

code/modules/religion/burdened/psyker.dm

@@ -10,12 +10,12 @@
 	organ_traits = list(TRAIT_ADVANCEDTOOLUSER, TRAIT_LITERATE, TRAIT_CAN_STRIP, TRAIT_ANTIMAGIC_NO_SELFBLOCK)
 	w_class = WEIGHT_CLASS_NORMAL
 
-/obj/item/organ/internal/brain/psyker/on_insert(mob/living/carbon/inserted_into)
+/obj/item/organ/internal/brain/psyker/on_mob_insert(mob/living/carbon/inserted_into)
 	. = ..()
 	inserted_into.AddComponent(/datum/component/echolocation, blocking_trait = TRAIT_DUMB, echo_group = "psyker", echo_icon = "psyker", color_path = /datum/client_colour/psyker)
 	inserted_into.AddComponent(/datum/component/anti_magic, antimagic_flags = MAGIC_RESISTANCE_MIND)
 
-/obj/item/organ/internal/brain/psyker/on_remove(mob/living/carbon/removed_from)
+/obj/item/organ/internal/brain/psyker/on_mob_remove(mob/living/carbon/removed_from)
 	. = ..()
 	qdel(removed_from.GetComponent(/datum/component/echolocation))
 	qdel(removed_from.GetComponent(/datum/component/anti_magic))
@@ -82,9 +82,9 @@
 	qdel(old_head)
 	var/obj/item/organ/internal/brain/psyker/psyker_brain = new()
 	old_brain.before_organ_replacement(psyker_brain)
-	old_brain.Remove(src, special = TRUE, no_id_transfer = TRUE)
+	old_brain.Remove(src, special = TRUE, movement_flags = NO_ID_TRANSFER)
 	qdel(old_brain)
-	psyker_brain.Insert(src, special = TRUE, drop_if_replaced = FALSE)
+	psyker_brain.Insert(src, special = TRUE, movement_flags = DELETE_IF_REPLACED)
 	if(old_eyes)
 		qdel(old_eyes)
 	return TRUE

code/modules/spells/spell_types/self/summonitem.dm

@@ -138,7 +138,6 @@
 					item_to_retrieve = null
 					break
 
-				SEND_SIGNAL(holding_mark, COMSIG_MAGIC_RECALL, caster, item_to_retrieve)
 				holding_mark.dropItemToGround(item_to_retrieve)
 
 			else if(isobj(item_to_retrieve.loc))
@@ -157,15 +156,6 @@
 
 			infinite_recursion += 1
 
-	else
-		// Organs are usually stored in nullspace
-		if(isorgan(item_to_retrieve))
-			var/obj/item/organ/organ = item_to_retrieve
-			if(organ.owner)
-				// If this code ever runs I will be happy
-				log_combat(caster, organ.owner, "magically removed [organ.name] from", addition = "COMBAT MODE: [uppertext(caster.combat_mode)]")
-				organ.Remove(organ.owner)
-
 	if(!item_to_retrieve)
 		return
 
@@ -176,6 +166,8 @@
 	else
 		item_to_retrieve.forceMove(caster.drop_location())
 		item_to_retrieve.loc.visible_message(span_warning("[item_to_retrieve] suddenly appears!"))
+
+	SEND_SIGNAL(item_to_retrieve, COMSIG_MAGIC_RECALL, caster, item_to_retrieve)
 	playsound(get_turf(item_to_retrieve), 'sound/magic/summonitems_generic.ogg', 50, TRUE)
 
 /datum/action/cooldown/spell/summonitem/abductor

code/modules/surgery/bodyparts/_bodyparts.dm

@@ -6,6 +6,7 @@
 	w_class = WEIGHT_CLASS_SMALL
 	icon = 'icons/mob/human/bodyparts.dmi'
 	icon_state = "" //Leave this blank! Bodyparts are built using overlays
+	flags_1 = PREVENT_CONTENTS_EXPLOSION_1 //actually mindblowing
 	/// The icon for Organic limbs using greyscale
 	VAR_PROTECTED/icon_greyscale = DEFAULT_BODYPART_ICON_ORGANIC
 	///The icon for non-greyscale limbs
@@ -19,7 +20,7 @@
 	layer = BELOW_MOB_LAYER //so it isn't hidden behind objects when on the floor
 	grind_results = list(/datum/reagent/bone_dust = 10, /datum/reagent/consumable/liquidgibs = 5) // robotic bodyparts and chests/heads cannot be ground
 	/// The mob that "owns" this limb
-	/// DO NOT MODIFY DIRECTLY. Use set_owner()
+	/// DO NOT MODIFY DIRECTLY. Use update_owner()
 	var/mob/living/carbon/owner
 
 	/// If this limb can be scarred.
@@ -155,9 +156,6 @@
 	/// If something is currently grasping this bodypart and trying to staunch bleeding (see [/obj/item/hand_item/self_grasp])
 	var/obj/item/hand_item/self_grasp/grasped_by
 
-	///A list of all the external organs we've got stored to draw horns, wings and stuff with (special because we are actually in the limbs unlike normal organs :/ )
-	///If someone ever comes around to making all organs exist in the bodyparts, you can just remove this and use a typed loop
-	var/list/obj/item/organ/external/external_organs = list()
 	///A list of all bodypart overlays to draw
 	var/list/bodypart_overlays = list()
 
@@ -232,31 +230,40 @@
 	refresh_bleed_rate()
 
 /obj/item/bodypart/Destroy()
-	if(owner)
-		owner.remove_bodypart(src)
-		set_owner(null)
+	if(owner && !QDELETED(owner))
+		forced_removal(special = FALSE, dismembered = TRUE, move_to_floor = FALSE)
+		update_owner(null)
 	for(var/wound in wounds)
 		qdel(wound) // wounds is a lazylist, and each wound removes itself from it on deletion.
 	if(length(wounds))
 		stack_trace("[type] qdeleted with [length(wounds)] uncleared wounds")
 		wounds.Cut()
 
-	if(length(external_organs))
-		for(var/obj/item/organ/external/external_organ as anything in external_organs)
-			external_organs -= external_organ
-			qdel(external_organ) // It handles removing its references to this limb on its own.
+	owner = null
+
+	for(var/atom/movable/movable in contents)
+		qdel(movable)
 
-		external_organs = list()
 	QDEL_LIST_ASSOC_VAL(feature_offsets)
 
 	return ..()
 
-/obj/item/bodypart/forceMove(atom/destination) //Please. Never forcemove a limb if its's actually in use. This is only for borgs.
-	SHOULD_CALL_PARENT(TRUE)
+/obj/item/bodypart/ex_act(severity, target)
+	if(owner) //trust me bro you dont want this
+		return FALSE
+	return  ..()
 
-	. = ..()
-	if(isturf(destination))
-		update_icon_dropped()
+
+/obj/item/bodypart/proc/on_forced_removal(atom/old_loc, dir, forced, list/old_locs)
+	SIGNAL_HANDLER
+
+	forced_removal(special = FALSE, dismembered = TRUE, move_to_floor = FALSE)
+
+/// In-case someone, somehow only teleports someones limb
+/obj/item/bodypart/proc/forced_removal(special, dismembered, move_to_floor)
+	drop_limb(special, dismembered, move_to_floor)
+
+	update_icon_dropped()
 
 /obj/item/bodypart/examine(mob/user)
 	SHOULD_CALL_PARENT(TRUE)
@@ -403,32 +410,25 @@
 	var/atom/drop_loc = drop_location()
 	if(IS_ORGANIC_LIMB(src))
 		playsound(drop_loc, 'sound/misc/splort.ogg', 50, TRUE, -1)
+
 	QDEL_NULL(current_gauze)
-	for(var/obj/item/organ/bodypart_organ as anything in get_organs())
-		bodypart_organ.transfer_to_limb(src, owner)
-	for(var/obj/item/organ/external/external as anything in external_organs)
-		external.remove_from_limb()
-		external.forceMove(drop_loc)
-	for(var/obj/item/item_in_bodypart in src)
-		item_in_bodypart.forceMove(drop_loc)
+
+	for(var/obj/item/organ/bodypart_organ in contents)
+		if(bodypart_organ.organ_flags & ORGAN_UNREMOVABLE)
+			continue
+		if(owner)
+			bodypart_organ.Remove(bodypart_organ.owner)
+		else
+			if(bodypart_organ.bodypart_remove(src))
+				if(drop_loc) //can be null if being deleted
+					bodypart_organ.forceMove(get_turf(drop_loc))
+
+	if(drop_loc) //can be null during deletion
+		for(var/atom/movable/movable as anything in src)
+			movable.forceMove(drop_loc)
 
 	update_icon_dropped()
 
-///since organs aren't actually stored in the bodypart themselves while attached to a person, we have to query the owner for what we should have
-/obj/item/bodypart/proc/get_organs()
-	SHOULD_CALL_PARENT(TRUE)
-	RETURN_TYPE(/list)
-
-	if(!owner)
-		return FALSE
-
-	var/list/bodypart_organs
-	for(var/obj/item/organ/organ_check as anything in owner.organs) //internal organs inside the dismembered limb are dropped.
-		if(check_zone(organ_check.zone) == body_zone)
-			LAZYADD(bodypart_organs, organ_check) // this way if we don't have any, it'll just return null
-
-	return bodypart_organs
-
 //Return TRUE to get whatever mob this is in to update health.
 /obj/item/bodypart/proc/on_life(seconds_per_tick, times_fired)
 	SHOULD_CALL_PARENT(TRUE)
@@ -737,70 +737,91 @@
 	owner.update_health_hud() //update the healthdoll
 	owner.update_body()
 
-///Proc to change the value of the `owner` variable and react to the event of its change.
-/obj/item/bodypart/proc/set_owner(new_owner)
-	SHOULD_CALL_PARENT(TRUE)
+/// Proc to change the value of the `owner` variable and react to the event of its change.
+/obj/item/bodypart/proc/update_owner(new_owner)
+	SHOULD_NOT_OVERRIDE(TRUE)
+
 	if(owner == new_owner)
 		return FALSE //`null` is a valid option, so we need to use a num var to make it clear no change was made.
-	var/mob/living/carbon/old_owner = owner
-	owner = new_owner
-	SEND_SIGNAL(src, COMSIG_BODYPART_CHANGED_OWNER, new_owner, old_owner)
-	var/needs_update_disabled = FALSE //Only really relevant if there's an owner
-	if(old_owner)
-		if(held_index)
-			old_owner.on_lost_hand(src)
-			if(old_owner.hud_used)
-				var/atom/movable/screen/inventory/hand/hand = old_owner.hud_used.hand_slots["[held_index]"]
-				if(hand)
-					hand.update_appearance()
-			old_owner.update_worn_gloves()
-		if(speed_modifier)
-			old_owner.update_bodypart_speed_modifier()
-		if(length(bodypart_traits))
-			old_owner.remove_traits(bodypart_traits, bodypart_trait_source)
-		if(initial(can_be_disabled))
-			if(HAS_TRAIT(old_owner, TRAIT_NOLIMBDISABLE))
-				if(!owner || !HAS_TRAIT(owner, TRAIT_NOLIMBDISABLE))
-					set_can_be_disabled(initial(can_be_disabled))
-					needs_update_disabled = TRUE
-			UnregisterSignal(old_owner, list(
-				SIGNAL_REMOVETRAIT(TRAIT_NOLIMBDISABLE),
-				SIGNAL_ADDTRAIT(TRAIT_NOLIMBDISABLE),
-				SIGNAL_REMOVETRAIT(TRAIT_NOBLOOD),
-				SIGNAL_ADDTRAIT(TRAIT_NOBLOOD),
-				))
-		UnregisterSignal(old_owner, COMSIG_ATOM_RESTYLE)
+
+	SEND_SIGNAL(src, COMSIG_BODYPART_CHANGED_OWNER, new_owner, owner)
+
 	if(owner)
-		if(held_index)
-			owner.on_added_hand(src, held_index)
-			if(owner.hud_used)
-				var/atom/movable/screen/inventory/hand/hand = owner.hud_used.hand_slots["[held_index]"]
-				if(hand)
-					hand.update_appearance()
-			owner.update_worn_gloves()
-		if(speed_modifier)
-			owner.update_bodypart_speed_modifier()
-		if(length(bodypart_traits))
-			owner.add_traits(bodypart_traits, bodypart_trait_source)
-		if(initial(can_be_disabled))
-			if(HAS_TRAIT(owner, TRAIT_NOLIMBDISABLE))
-				set_can_be_disabled(FALSE)
-				needs_update_disabled = FALSE
-			RegisterSignal(owner, SIGNAL_REMOVETRAIT(TRAIT_NOLIMBDISABLE), PROC_REF(on_owner_nolimbdisable_trait_loss))
-			RegisterSignal(owner, SIGNAL_ADDTRAIT(TRAIT_NOLIMBDISABLE), PROC_REF(on_owner_nolimbdisable_trait_gain))
-			// Bleeding stuff
-			RegisterSignal(owner, SIGNAL_REMOVETRAIT(TRAIT_NOBLOOD), PROC_REF(on_owner_nobleed_loss))
-			RegisterSignal(owner, SIGNAL_ADDTRAIT(TRAIT_NOBLOOD), PROC_REF(on_owner_nobleed_gain))
-
-		if(needs_update_disabled)
-			update_disabled()
-
-		RegisterSignal(owner, COMSIG_ATOM_RESTYLE, PROC_REF(on_attempt_feature_restyle_mob))
+		. = owner //return value is old owner
+		clear_ownership(owner)
+	if(new_owner)
+		apply_ownership(new_owner)
 
 	refresh_bleed_rate()
-	return old_owner
+	return .
+
+/// Run all necessary procs to remove a limbs ownership and remove the appropriate signals and traits
+/obj/item/bodypart/proc/clear_ownership(mob/living/carbon/old_owner)
+	SHOULD_CALL_PARENT(TRUE)
+
+	owner = null
+
+	if(speed_modifier)
+		old_owner.update_bodypart_speed_modifier()
+	if(length(bodypart_traits))
+		old_owner.remove_traits(bodypart_traits, bodypart_trait_source)
+
+	UnregisterSignal(old_owner, list(
+		SIGNAL_REMOVETRAIT(TRAIT_NOLIMBDISABLE),
+	SIGNAL_ADDTRAIT(TRAIT_NOLIMBDISABLE),
+		SIGNAL_REMOVETRAIT(TRAIT_NOBLOOD),
+		SIGNAL_ADDTRAIT(TRAIT_NOBLOOD),
+		))
+
+	UnregisterSignal(old_owner, COMSIG_ATOM_RESTYLE)
+
+/// Apply ownership of a limb to someone, giving the appropriate traits, updates and signals
+/obj/item/bodypart/proc/apply_ownership(mob/living/carbon/new_owner)
+	SHOULD_CALL_PARENT(TRUE)
+
+	owner = new_owner
+
+	if(speed_modifier)
+		owner.update_bodypart_speed_modifier()
+	if(length(bodypart_traits))
+		owner.add_traits(bodypart_traits, bodypart_trait_source)
+
+	if(initial(can_be_disabled))
+		if(HAS_TRAIT(owner, TRAIT_NOLIMBDISABLE))
+			set_can_be_disabled(FALSE)
+
+		// Listen to disable traits being added
+		RegisterSignal(owner, SIGNAL_REMOVETRAIT(TRAIT_NOLIMBDISABLE), PROC_REF(on_owner_nolimbdisable_trait_loss))
+		RegisterSignal(owner, SIGNAL_ADDTRAIT(TRAIT_NOLIMBDISABLE), PROC_REF(on_owner_nolimbdisable_trait_gain))
+
+		// Listen to no blood traits being added
+		RegisterSignal(owner, SIGNAL_REMOVETRAIT(TRAIT_NOBLOOD), PROC_REF(on_owner_nobleed_loss))
+		RegisterSignal(owner, SIGNAL_ADDTRAIT(TRAIT_NOBLOOD), PROC_REF(on_owner_nobleed_gain))
+
+	if(can_be_disabled)
+		update_disabled()
+
+	RegisterSignal(owner, COMSIG_ATOM_RESTYLE, PROC_REF(on_attempt_feature_restyle_mob))
+
+	forceMove(owner)
+	RegisterSignal(src, COMSIG_MOVABLE_MOVED, PROC_REF(on_forced_removal)) //this must be set after we moved, or we insta gib
+
+/// Called on addition of a bodypart
+/obj/item/bodypart/proc/on_adding(mob/living/carbon/new_owner)
+	SHOULD_CALL_PARENT(TRUE)
+
+	item_flags |= ABSTRACT
+	ADD_TRAIT(src, TRAIT_NODROP, ORGAN_INSIDE_BODY_TRAIT)
+
+/// Called on removal of a bodypart.
+/obj/item/bodypart/proc/on_removal(mob/living/carbon/old_owner)
+	SHOULD_CALL_PARENT(TRUE)
+
+	UnregisterSignal(src, COMSIG_MOVABLE_MOVED)
+
+	item_flags &= ~ABSTRACT
+	REMOVE_TRAIT(src, TRAIT_NODROP, ORGAN_INSIDE_BODY_TRAIT)
 
-/obj/item/bodypart/proc/on_removal()
 	if(!length(bodypart_traits))
 		return
 

code/modules/surgery/bodyparts/dismemberment.dm

@@ -67,7 +67,7 @@
 	if(wounding_type != WOUND_BURN && isturf(chest_owner.loc) && can_bleed())
 		chest_owner.add_splatter_floor(chest_owner.loc)
 	playsound(get_turf(chest_owner), 'sound/misc/splort.ogg', 80, TRUE)
-	for(var/obj/item/organ/organ as anything in chest_owner.organs)
+	for(var/obj/item/organ/organ in contents)
 		var/org_zone = check_zone(organ.zone)
 		if(org_zone != BODY_ZONE_CHEST)
 			continue
@@ -75,21 +75,13 @@
 		organ.forceMove(chest_owner.loc)
 		. += organ
 
-	for(var/obj/item/organ/external/ext_organ as anything in src.external_organs)
-		if(!(ext_organ.organ_flags & ORGAN_UNREMOVABLE))
-			ext_organ.Remove(chest_owner)
-			ext_organ.forceMove(chest_owner.loc)
-			. += ext_organ
-
 	if(cavity_item)
 		cavity_item.forceMove(chest_owner.loc)
 		. += cavity_item
 		cavity_item = null
 
-	return .
-
 ///limb removal. The "special" argument is used for swapping a limb with a new one without the effects of losing a limb kicking in.
-/obj/item/bodypart/proc/drop_limb(special, dismembered)
+/obj/item/bodypart/proc/drop_limb(special, dismembered, move_to_floor = TRUE)
 	if(!owner)
 		return
 	var/atom/drop_loc = owner.drop_location()
@@ -98,16 +90,13 @@
 	SEND_SIGNAL(src, COMSIG_BODYPART_REMOVED, owner, special, dismembered)
 	update_limb(dropping_limb = TRUE)
 	bodypart_flags &= ~BODYPART_IMPLANTED //limb is out and about, it can't really be considered an implant
-	owner.remove_bodypart(src)
+	owner.remove_bodypart(src, special)
 
 	for(var/datum/scar/scar as anything in scars)
 		scar.victim = null
 		LAZYREMOVE(owner.all_scars, scar)
 
-	for(var/obj/item/organ/external/ext_organ as anything in external_organs)
-		ext_organ.transfer_to_limb(src, null) //Null is the second arg because the bodypart is being removed from it's owner.
-
-	var/mob/living/carbon/phantom_owner = set_owner(null) // so we can still refer to the guy who lost their limb after said limb forgets 'em
+	var/mob/living/carbon/phantom_owner = update_owner(null) // so we can still refer to the guy who lost their limb after said limb forgets 'em
 
 	for(var/datum/wound/wound as anything in wounds)
 		wound.remove_wound(TRUE)
@@ -131,27 +120,22 @@
 					to_chat(phantom_owner, span_warning("You feel your [mutation] deactivating from the loss of your [body_zone]!"))
 					phantom_owner.dna.force_lose(mutation)
 
-		for(var/obj/item/organ/organ as anything in phantom_owner.organs) //internal organs inside the dismembered limb are dropped.
-			var/org_zone = check_zone(organ.zone)
-			if(org_zone != body_zone)
-				continue
-			organ.transfer_to_limb(src, phantom_owner)
-
 	update_icon_dropped()
 	phantom_owner.update_health_hud() //update the healthdoll
 	phantom_owner.update_body()
 	phantom_owner.update_body_parts()
 
-	if(!drop_loc) // drop_loc = null happens when a "dummy human" used for rendering icons on prefs screen gets its limbs replaced.
-		qdel(src)
-		return
-
 	if(bodypart_flags & BODYPART_PSEUDOPART)
 		drop_organs(phantom_owner) //Psuedoparts shouldn't have organs, but just in case
 		qdel(src)
 		return
 
-	forceMove(drop_loc)
+	if(move_to_floor)
+		if(!drop_loc) // drop_loc = null happens when a "dummy human" used for rendering icons on prefs screen gets its limbs replaced.
+			qdel(src)
+			return
+		forceMove(drop_loc)
+
 	SEND_SIGNAL(phantom_owner, COMSIG_CARBON_POST_REMOVE_LIMB, src, special, dismembered)
 
 /**
@@ -201,48 +185,45 @@
 		var/datum/wound/loss/dismembering = new
 		return dismembering.apply_dismember(src, wounding_type)
 
-///Transfers the organ to the limb, and to the limb's owner, if it has one. This is done on drop_limb().
-/obj/item/organ/proc/transfer_to_limb(obj/item/bodypart/bodypart, mob/living/carbon/bodypart_owner)
-	Remove(bodypart_owner)
-	add_to_limb(bodypart)
-
-///Adds the organ to a bodypart, used in transfer_to_limb()
-/obj/item/organ/proc/add_to_limb(obj/item/bodypart/bodypart)
-	forceMove(bodypart)
-
-///Removes the organ from the limb, placing it into nullspace.
-/obj/item/organ/proc/remove_from_limb()
-	moveToNullspace()
-
-/obj/item/organ/internal/brain/transfer_to_limb(obj/item/bodypart/head/head, mob/living/carbon/human/head_owner)
-	Remove(head_owner) //Changeling brain concerns are now handled in Remove
-	forceMove(head)
-	head.brain = src
-	if(brainmob)
-		head.brainmob = brainmob
-		brainmob = null
-		head.brainmob.forceMove(head)
-		head.brainmob.set_stat(DEAD)
-
-/obj/item/organ/internal/eyes/transfer_to_limb(obj/item/bodypart/head/head, mob/living/carbon/human/head_owner)
+/obj/item/organ/internal/eyes/on_bodypart_insert(obj/item/bodypart/head/head)
 	head.eyes = src
 	..()
 
-/obj/item/organ/internal/ears/transfer_to_limb(obj/item/bodypart/head/head, mob/living/carbon/human/head_owner)
+/obj/item/organ/internal/ears/on_bodypart_insert(obj/item/bodypart/head/head)
 	head.ears = src
 	..()
 
-/obj/item/organ/internal/tongue/transfer_to_limb(obj/item/bodypart/head/head, mob/living/carbon/human/head_owner)
+/obj/item/organ/internal/tongue/on_bodypart_insert(obj/item/bodypart/head/head)
 	head.tongue = src
 	..()
 
-/obj/item/bodypart/chest/drop_limb(special)
+/obj/item/organ/internal/brain/on_bodypart_insert(obj/item/bodypart/head/head)
+	head.brain = src
+	..()
+
+/obj/item/organ/internal/eyes/on_bodypart_remove(obj/item/bodypart/head/head)
+	head.eyes = null
+	..()
+
+/obj/item/organ/internal/ears/on_bodypart_remove(obj/item/bodypart/head/head)
+	head.ears = null
+	..()
+
+/obj/item/organ/internal/tongue/on_bodypart_remove(obj/item/bodypart/head/head)
+	head.tongue = null
+	..()
+
+/obj/item/organ/internal/brain/on_bodypart_remove(obj/item/bodypart/head/head)
+	head.brain = null
+	..()
+
+/obj/item/bodypart/chest/drop_limb(special, dismembered, move_to_floor = TRUE)
 	if(special)
 		return ..()
 	//if this is not a special drop, this is a mistake
 	return FALSE
 
-/obj/item/bodypart/arm/drop_limb(special)
+/obj/item/bodypart/arm/drop_limb(special, dismembered, move_to_floor = TRUE)
 	var/mob/living/carbon/arm_owner = owner
 
 	if(special || !arm_owner)
@@ -265,7 +246,7 @@
 	arm_owner.update_worn_gloves() //to remove the bloody hands overlay
 	return ..()
 
-/obj/item/bodypart/leg/drop_limb(special)
+/obj/item/bodypart/leg/drop_limb(special, dismembered, move_to_floor = TRUE)
 	if(owner && !special)
 		if(owner.legcuffed)
 			owner.legcuffed.forceMove(owner.drop_location()) //At this point bodypart is still in nullspace
@@ -276,7 +257,7 @@
 			owner.dropItemToGround(owner.shoes, TRUE)
 	return ..()
 
-/obj/item/bodypart/head/drop_limb(special)
+/obj/item/bodypart/head/drop_limb(special, dismembered, move_to_floor = TRUE)
 	if(!special)
 		//Drop all worn head items
 		for(var/obj/item/head_item as anything in list(owner.glasses, owner.ears, owner.wear_mask, owner.head))
@@ -332,8 +313,6 @@
 
 	SEND_SIGNAL(new_limb_owner, COMSIG_CARBON_ATTACH_LIMB, src, special)
 	SEND_SIGNAL(src, COMSIG_BODYPART_ATTACHED, new_limb_owner, special)
-	moveToNullspace()
-	set_owner(new_limb_owner)
 	new_limb_owner.add_bodypart(src)
 
 	LAZYREMOVE(new_limb_owner.body_zone_dismembered_by, body_zone)
@@ -346,8 +325,10 @@
 				qdel(attach_surgery)
 				break
 
-	for(var/obj/item/organ/limb_organ in contents)
-		limb_organ.Insert(new_limb_owner, TRUE)
+		for(var/obj/item/organ/organ as anything in new_limb_owner.organs)
+			if(deprecise_zone(organ.zone) != body_zone)
+				continue
+			organ.bodypart_insert(src)
 
 	for(var/datum/wound/wound as anything in wounds)
 		// we have to remove the wound from the limb wound list first, so that we can reapply it fresh with the new person
@@ -387,15 +368,6 @@
 	if(!.)
 		return
 
-	if(brain)
-		brain = null
-	if(tongue)
-		tongue = null
-	if(ears)
-		ears = null
-	if(eyes)
-		eyes = null
-
 	if(old_real_name)
 		new_head_owner.real_name = old_real_name
 	real_name = new_head_owner.real_name

code/modules/surgery/bodyparts/head.dm

@@ -26,7 +26,6 @@
 	unarmed_effectiveness = 0
 	bodypart_trait_source = HEAD_TRAIT
 
-	var/mob/living/brain/brainmob //The current occupant.
 	var/obj/item/organ/internal/brain/brain //The brain organ
 	var/obj/item/organ/internal/eyes/eyes
 	var/obj/item/organ/internal/ears/ears
@@ -93,12 +92,6 @@
 	var/datum/worn_feature_offset/worn_face_offset
 
 /obj/item/bodypart/head/Destroy()
-	QDEL_NULL(brainmob) //order is sensitive, see warning in Exited() below
-	QDEL_NULL(brain)
-	QDEL_NULL(eyes)
-	QDEL_NULL(ears)
-	QDEL_NULL(tongue)
-
 	QDEL_NULL(worn_ears_offset)
 	QDEL_NULL(worn_glasses_offset)
 	QDEL_NULL(worn_mask_offset)
@@ -110,11 +103,6 @@
 	if(gone == brain)
 		brain = null
 		update_icon_dropped()
-		if(!QDELETED(brainmob)) //this shouldn't happen without badminnery.
-			message_admins("Brainmob: ([ADMIN_LOOKUPFLW(brainmob)]) was left stranded in [src] at [ADMIN_VERBOSEJMP(src)] without a brain!")
-			brainmob.log_message(", brainmob, was left stranded in [src] without a brain", LOG_GAME)
-	if(gone == brainmob)
-		brainmob = null
 	if(gone == eyes)
 		eyes = null
 		update_icon_dropped()
@@ -129,12 +117,12 @@
 	if(show_organs_on_examine && IS_ORGANIC_LIMB(src))
 		if(!brain)
 			. += span_info("The brain has been removed from [src].")
-		else if(brain.suicided || (brainmob && HAS_TRAIT(brainmob, TRAIT_SUICIDED)))
+		else if(brain.suicided || (brain.brainmob && HAS_TRAIT(brain.brainmob, TRAIT_SUICIDED)))
 			. += span_info("There's a miserable expression on [real_name]'s face; they must have really hated life. There's no hope of recovery.")
-		else if(brainmob?.health <= HEALTH_THRESHOLD_DEAD)
-			. += span_info("It's leaking some kind of... clear fluid? The brain inside must be in pretty bad shape.")
-		else if(brainmob)
-			if(brainmob.key || brainmob.get_ghost(FALSE, TRUE))
+		else if(brain.brainmob)
+			if(brain.brainmob?.health <= HEALTH_THRESHOLD_DEAD)
+				. += span_info("It's leaking some kind of... clear fluid? The brain inside must be in pretty bad shape.")
+			if(brain.brainmob.key || brain.brainmob.get_ghost(FALSE, TRUE))
 				. += span_info("Its muscles are twitching slightly... It seems to have some life still in it.")
 			else
 				. += span_info("It's completely lifeless. Perhaps there'll be a chance for them later.")
@@ -158,33 +146,12 @@
 	return ..()
 
 /obj/item/bodypart/head/drop_organs(mob/user, violent_removal)
-	var/atom/drop_loc = drop_location()
-	for(var/obj/item/head_item in src)
-		if(head_item == brain)
-			if(user)
-				user.visible_message(span_warning("[user] saws [src] open and pulls out a brain!"), span_notice("You saw [src] open and pull out a brain."))
-			if(brainmob)
-				brainmob.container = null
-				brain.brainmob = brainmob
-				brainmob = null
-			if(violent_removal && prob(rand(80, 100))) //ghetto surgery can damage the brain.
-				to_chat(user, span_warning("[brain] was damaged in the process!"))
-				brain.set_organ_damage(brain.maxHealth)
-			brain.forceMove(drop_loc)
-			brain = null
-			update_icon_dropped()
-		else
-			if(istype(head_item, /obj/item/reagent_containers/pill))
-				for(var/datum/action/item_action/hands_free/activate_pill/pill_action in head_item.actions)
-					qdel(pill_action)
-			else if(isorgan(head_item))
-				var/obj/item/organ/organ = head_item
-				if(organ.organ_flags & ORGAN_UNREMOVABLE)
-					continue
-			head_item.forceMove(drop_loc)
-	eyes = null
-	ears = null
-	tongue = null
+	if(user)
+		user.visible_message(span_warning("[user] saws [src] open and pulls out a brain!"), span_notice("You saw [src] open and pull out a brain."))
+	if(brain && violent_removal && prob(90)) //ghetto surgery can damage the brain.
+		to_chat(user, span_warning("[brain] was damaged in the process!"))
+		brain.set_organ_damage(brain.maxHealth)
+
 	update_limb()
 	return ..()
 

code/modules/surgery/bodyparts/helpers.dm

@@ -15,6 +15,7 @@
 /mob/living/carbon/proc/del_and_replace_bodypart(obj/item/bodypart/new_limb, special)
 	var/obj/item/bodypart/old_limb = get_bodypart(new_limb.body_zone)
 	if(old_limb)
+		old_limb.drop_limb(special = TRUE)
 		qdel(old_limb)
 	new_limb.try_attach_limb(src, special = special)
 
@@ -172,7 +173,7 @@
 /mob/living/carbon/proc/synchronize_bodytypes()
 	var/all_limb_flags = NONE
 	for(var/obj/item/bodypart/limb as anything in bodyparts)
-		for(var/obj/item/organ/external/ext_organ as anything in limb.external_organs)
+		for(var/obj/item/organ/external/ext_organ in limb)
 			all_limb_flags |= ext_organ.external_bodytypes
 		all_limb_flags |= limb.bodytype
 

code/modules/surgery/bodyparts/parts.dm

@@ -35,8 +35,18 @@
 	/// Which functional (i.e. flightpotion) wing types (if any) does this bodypart support? If count is >1 a radial menu is used to choose between all icons in list
 	var/list/wing_types = list(/obj/item/organ/external/wings/functional/angel)
 
+/obj/item/bodypart/chest/forced_removal(dismembered, special, move_to_floor)
+	var/mob/living/carbon/old_owner = owner
+	..(special = TRUE) //special because we're self destructing
+
+	//If someones chest is teleported away, they die pretty hard
+	if(!old_owner)
+		return
+	message_admins("[ADMIN_LOOKUPFLW(old_owner)] was gibbed after their chest teleport to [ADMIN_VERBOSEJMP(loc)].")
+	old_owner.gib(DROP_ALL_REMAINS)
+
 /obj/item/bodypart/chest/can_dismember(obj/item/item)
-	if(owner.stat < HARD_CRIT || !get_organs())
+	if(owner.stat < HARD_CRIT || !contents.len)
 		return FALSE
 	return ..()
 
@@ -127,6 +137,40 @@
 	QDEL_NULL(held_hand_offset)
 	return ..()
 
+/// We need to clear out hand hud items and appearance, so do that here
+/obj/item/bodypart/arm/clear_ownership(mob/living/carbon/old_owner)
+	..()
+
+	old_owner.update_worn_gloves()
+
+	if(!held_index)
+		return
+
+	old_owner.on_lost_hand(src)
+
+	if(!old_owner.hud_used)
+		return
+
+	var/atom/movable/screen/inventory/hand/hand = old_owner.hud_used.hand_slots["[held_index]"]
+	hand?.update_appearance()
+
+/// We need to add hand hud items and appearance, so do that here
+/obj/item/bodypart/arm/apply_ownership(mob/living/carbon/new_owner)
+	..()
+
+	new_owner.update_worn_gloves()
+
+	if(!held_index)
+		return
+
+	new_owner.on_added_hand(src, held_index)
+
+	if(!new_owner.hud_used)
+		return
+
+	var/atom/movable/screen/inventory/hand/hand = new_owner.hud_used.hand_slots["[held_index]"]
+	hand.update_appearance()
+
 /obj/item/bodypart/arm/left
 	name = "left arm"
 	desc = "Did you know that the word 'sinister' stems originally from the \
@@ -143,27 +187,22 @@
 	px_y = 0
 	bodypart_trait_source = LEFT_ARM_TRAIT
 
+/obj/item/bodypart/arm/left/apply_ownership(mob/living/carbon/new_owner)
+	if(HAS_TRAIT(new_owner, TRAIT_PARALYSIS_L_ARM))
+		ADD_TRAIT(src, TRAIT_PARALYSIS, TRAIT_PARALYSIS_L_ARM)
+		RegisterSignal(new_owner, SIGNAL_REMOVETRAIT(TRAIT_PARALYSIS_L_ARM), PROC_REF(on_owner_paralysis_loss))
+	else
+		REMOVE_TRAIT(src, TRAIT_PARALYSIS, TRAIT_PARALYSIS_L_ARM)
+		RegisterSignal(new_owner, SIGNAL_ADDTRAIT(TRAIT_PARALYSIS_L_ARM), PROC_REF(on_owner_paralysis_gain))
+	..()
 
-/obj/item/bodypart/arm/left/set_owner(new_owner)
-	. = ..()
-	if(. == FALSE)
-		return
-	if(owner)
-		if(HAS_TRAIT(owner, TRAIT_PARALYSIS_L_ARM))
-			ADD_TRAIT(src, TRAIT_PARALYSIS, TRAIT_PARALYSIS_L_ARM)
-			RegisterSignal(owner, SIGNAL_REMOVETRAIT(TRAIT_PARALYSIS_L_ARM), PROC_REF(on_owner_paralysis_loss))
-		else
-			REMOVE_TRAIT(src, TRAIT_PARALYSIS, TRAIT_PARALYSIS_L_ARM)
-			RegisterSignal(owner, SIGNAL_ADDTRAIT(TRAIT_PARALYSIS_L_ARM), PROC_REF(on_owner_paralysis_gain))
-	if(.)
-		var/mob/living/carbon/old_owner = .
-		if(HAS_TRAIT(old_owner, TRAIT_PARALYSIS_L_ARM))
-			UnregisterSignal(old_owner, SIGNAL_REMOVETRAIT(TRAIT_PARALYSIS_L_ARM))
-			if(!owner || !HAS_TRAIT(owner, TRAIT_PARALYSIS_L_ARM))
-				REMOVE_TRAIT(src, TRAIT_PARALYSIS, TRAIT_PARALYSIS_L_ARM)
-		else
-			UnregisterSignal(old_owner, SIGNAL_ADDTRAIT(TRAIT_PARALYSIS_L_ARM))
-
+/obj/item/bodypart/arm/left/clear_ownership(mob/living/carbon/old_owner)
+	if(HAS_TRAIT(old_owner, TRAIT_PARALYSIS_L_ARM))
+		UnregisterSignal(old_owner, SIGNAL_REMOVETRAIT(TRAIT_PARALYSIS_L_ARM))
+		REMOVE_TRAIT(src, TRAIT_PARALYSIS, TRAIT_PARALYSIS_L_ARM)
+	else
+		UnregisterSignal(old_owner, SIGNAL_ADDTRAIT(TRAIT_PARALYSIS_L_ARM))
+	..()
 
 ///Proc to react to the owner gaining the TRAIT_PARALYSIS_L_ARM trait.
 /obj/item/bodypart/arm/left/proc/on_owner_paralysis_gain(mob/living/carbon/source)
@@ -172,7 +211,6 @@
 	UnregisterSignal(owner, SIGNAL_ADDTRAIT(TRAIT_PARALYSIS_L_ARM))
 	RegisterSignal(owner, SIGNAL_REMOVETRAIT(TRAIT_PARALYSIS_L_ARM), PROC_REF(on_owner_paralysis_loss))
 
-
 ///Proc to react to the owner losing the TRAIT_PARALYSIS_L_ARM trait.
 /obj/item/bodypart/arm/left/proc/on_owner_paralysis_loss(mob/living/carbon/source)
 	SIGNAL_HANDLER
@@ -180,7 +218,6 @@
 	UnregisterSignal(owner, SIGNAL_REMOVETRAIT(TRAIT_PARALYSIS_L_ARM))
 	RegisterSignal(owner, SIGNAL_ADDTRAIT(TRAIT_PARALYSIS_L_ARM), PROC_REF(on_owner_paralysis_gain))
 
-
 /obj/item/bodypart/arm/left/set_disabled(new_disabled)
 	. = ..()
 	if(isnull(.) || !owner)
@@ -200,7 +237,6 @@
 		var/atom/movable/screen/inventory/hand/hand_screen_object = owner.hud_used.hand_slots["[held_index]"]
 		hand_screen_object?.update_appearance()
 
-
 /obj/item/bodypart/arm/left/monkey
 	icon = 'icons/mob/human/species/monkey/bodyparts.dmi'
 	icon_static = 'icons/mob/human/species/monkey/bodyparts.dmi'
@@ -233,7 +269,6 @@
 	should_draw_greyscale = FALSE
 	appendage_noun = "scythe-like hand"
 
-
 /obj/item/bodypart/arm/right
 	name = "right arm"
 	desc = "Over 87% of humans are right handed. That figure is much lower \
@@ -249,26 +284,22 @@
 	px_y = 0
 	bodypart_trait_source = RIGHT_ARM_TRAIT
 
-/obj/item/bodypart/arm/right/set_owner(new_owner)
-	. = ..()
-	if(. == FALSE)
-		return
-	if(owner)
-		if(HAS_TRAIT(owner, TRAIT_PARALYSIS_R_ARM))
-			ADD_TRAIT(src, TRAIT_PARALYSIS, TRAIT_PARALYSIS_R_ARM)
-			RegisterSignal(owner, SIGNAL_REMOVETRAIT(TRAIT_PARALYSIS_R_ARM), PROC_REF(on_owner_paralysis_loss))
-		else
-			REMOVE_TRAIT(src, TRAIT_PARALYSIS, TRAIT_PARALYSIS_R_ARM)
-			RegisterSignal(owner, SIGNAL_ADDTRAIT(TRAIT_PARALYSIS_R_ARM), PROC_REF(on_owner_paralysis_gain))
-	if(.)
-		var/mob/living/carbon/old_owner = .
-		if(HAS_TRAIT(old_owner, TRAIT_PARALYSIS_R_ARM))
-			UnregisterSignal(old_owner, SIGNAL_REMOVETRAIT(TRAIT_PARALYSIS_R_ARM))
-			if(!owner || !HAS_TRAIT(owner, TRAIT_PARALYSIS_R_ARM))
-				REMOVE_TRAIT(src, TRAIT_PARALYSIS, TRAIT_PARALYSIS_R_ARM)
-		else
-			UnregisterSignal(old_owner, SIGNAL_ADDTRAIT(TRAIT_PARALYSIS_R_ARM))
+/obj/item/bodypart/arm/right/apply_ownership(mob/living/carbon/new_owner)
+	if(HAS_TRAIT(new_owner, TRAIT_PARALYSIS_R_ARM))
+		ADD_TRAIT(src, TRAIT_PARALYSIS, TRAIT_PARALYSIS_R_ARM)
+		RegisterSignal(new_owner, SIGNAL_REMOVETRAIT(TRAIT_PARALYSIS_R_ARM), PROC_REF(on_owner_paralysis_loss))
+	else
+		REMOVE_TRAIT(src, TRAIT_PARALYSIS, TRAIT_PARALYSIS_R_ARM)
+		RegisterSignal(new_owner, SIGNAL_ADDTRAIT(TRAIT_PARALYSIS_R_ARM), PROC_REF(on_owner_paralysis_gain))
+	..()
 
+/obj/item/bodypart/arm/right/clear_ownership(mob/living/carbon/old_owner)
+	if(HAS_TRAIT(old_owner, TRAIT_PARALYSIS_R_ARM))
+		UnregisterSignal(old_owner, SIGNAL_REMOVETRAIT(TRAIT_PARALYSIS_R_ARM))
+		REMOVE_TRAIT(src, TRAIT_PARALYSIS, TRAIT_PARALYSIS_R_ARM)
+	else
+		UnregisterSignal(old_owner, SIGNAL_ADDTRAIT(TRAIT_PARALYSIS_R_ARM))
+	..()
 
 ///Proc to react to the owner gaining the TRAIT_PARALYSIS_R_ARM trait.
 /obj/item/bodypart/arm/right/proc/on_owner_paralysis_gain(mob/living/carbon/source)
@@ -277,7 +308,6 @@
 	UnregisterSignal(owner, SIGNAL_ADDTRAIT(TRAIT_PARALYSIS_R_ARM))
 	RegisterSignal(owner, SIGNAL_REMOVETRAIT(TRAIT_PARALYSIS_R_ARM), PROC_REF(on_owner_paralysis_loss))
 
-
 ///Proc to react to the owner losing the TRAIT_PARALYSIS_R_ARM trait.
 /obj/item/bodypart/arm/right/proc/on_owner_paralysis_loss(mob/living/carbon/source)
 	SIGNAL_HANDLER
@@ -285,7 +315,6 @@
 	UnregisterSignal(owner, SIGNAL_REMOVETRAIT(TRAIT_PARALYSIS_R_ARM))
 	RegisterSignal(owner, SIGNAL_ADDTRAIT(TRAIT_PARALYSIS_R_ARM), PROC_REF(on_owner_paralysis_gain))
 
-
 /obj/item/bodypart/arm/right/set_disabled(new_disabled)
 	. = ..()
 	if(isnull(.) || !owner)
@@ -305,7 +334,6 @@
 		var/atom/movable/screen/inventory/hand/hand_screen_object = owner.hud_used.hand_slots["[held_index]"]
 		hand_screen_object?.update_appearance()
 
-
 /obj/item/bodypart/arm/right/monkey
 	icon = 'icons/mob/human/species/monkey/bodyparts.dmi'
 	icon_static = 'icons/mob/human/species/monkey/bodyparts.dmi'
@@ -375,35 +403,30 @@
 	can_be_disabled = TRUE
 	bodypart_trait_source = LEFT_LEG_TRAIT
 
-/obj/item/bodypart/leg/left/set_owner(new_owner)
-	. = ..()
-	if(. == FALSE)
-		return
-	if(owner)
-		if(HAS_TRAIT(owner, TRAIT_PARALYSIS_L_LEG))
-			ADD_TRAIT(src, TRAIT_PARALYSIS, TRAIT_PARALYSIS_L_LEG)
-			RegisterSignal(owner, SIGNAL_REMOVETRAIT(TRAIT_PARALYSIS_L_LEG), PROC_REF(on_owner_paralysis_loss))
-		else
-			REMOVE_TRAIT(src, TRAIT_PARALYSIS, TRAIT_PARALYSIS_L_LEG)
-			RegisterSignal(owner, SIGNAL_ADDTRAIT(TRAIT_PARALYSIS_L_LEG), PROC_REF(on_owner_paralysis_gain))
-	if(.)
-		var/mob/living/carbon/old_owner = .
-		if(HAS_TRAIT(old_owner, TRAIT_PARALYSIS_L_LEG))
-			UnregisterSignal(old_owner, SIGNAL_REMOVETRAIT(TRAIT_PARALYSIS_L_LEG))
-			if(!owner || !HAS_TRAIT(owner, TRAIT_PARALYSIS_L_LEG))
-				REMOVE_TRAIT(src, TRAIT_PARALYSIS, TRAIT_PARALYSIS_L_LEG)
-		else
-			UnregisterSignal(old_owner, SIGNAL_ADDTRAIT(TRAIT_PARALYSIS_L_LEG))
+/obj/item/bodypart/leg/left/apply_ownership(mob/living/carbon/new_owner)
+	if(HAS_TRAIT(new_owner, TRAIT_PARALYSIS_L_LEG))
+		ADD_TRAIT(src, TRAIT_PARALYSIS, TRAIT_PARALYSIS_L_LEG)
+		RegisterSignal(new_owner, SIGNAL_REMOVETRAIT(TRAIT_PARALYSIS_L_LEG), PROC_REF(on_owner_paralysis_loss))
+	else
+		REMOVE_TRAIT(src, TRAIT_PARALYSIS, TRAIT_PARALYSIS_L_LEG)
+		RegisterSignal(new_owner, SIGNAL_ADDTRAIT(TRAIT_PARALYSIS_L_LEG), PROC_REF(on_owner_paralysis_gain))
+	..()
 
+/obj/item/bodypart/leg/left/clear_ownership(mob/living/carbon/old_owner)
+	if(HAS_TRAIT(old_owner, TRAIT_PARALYSIS_L_LEG))
+		UnregisterSignal(old_owner, SIGNAL_REMOVETRAIT(TRAIT_PARALYSIS_L_LEG))
+		REMOVE_TRAIT(src, TRAIT_PARALYSIS, TRAIT_PARALYSIS_L_LEG)
+	else
+		UnregisterSignal(old_owner, SIGNAL_ADDTRAIT(TRAIT_PARALYSIS_L_LEG))
+	..()
 
-///Proc to react to the owner gaining the TRAIT_PARALYSIS_L_LEG trait.
+///Proc to react to the owner gaining the TRAIT_PARALYSIS_L_ARM trait.
 /obj/item/bodypart/leg/left/proc/on_owner_paralysis_gain(mob/living/carbon/source)
 	SIGNAL_HANDLER
 	ADD_TRAIT(src, TRAIT_PARALYSIS, TRAIT_PARALYSIS_L_LEG)
 	UnregisterSignal(owner, SIGNAL_ADDTRAIT(TRAIT_PARALYSIS_L_LEG))
 	RegisterSignal(owner, SIGNAL_REMOVETRAIT(TRAIT_PARALYSIS_L_LEG), PROC_REF(on_owner_paralysis_loss))
 
-
 ///Proc to react to the owner losing the TRAIT_PARALYSIS_L_LEG trait.
 /obj/item/bodypart/leg/left/proc/on_owner_paralysis_loss(mob/living/carbon/source)
 	SIGNAL_HANDLER
@@ -411,7 +434,6 @@
 	UnregisterSignal(owner, SIGNAL_REMOVETRAIT(TRAIT_PARALYSIS_L_LEG))
 	RegisterSignal(owner, SIGNAL_ADDTRAIT(TRAIT_PARALYSIS_L_LEG), PROC_REF(on_owner_paralysis_gain))
 
-
 /obj/item/bodypart/leg/left/set_disabled(new_disabled)
 	. = ..()
 	if(isnull(.) || !owner)
@@ -469,26 +491,22 @@
 	px_y = 12
 	bodypart_trait_source = RIGHT_LEG_TRAIT
 
-/obj/item/bodypart/leg/right/set_owner(new_owner)
-	. = ..()
-	if(. == FALSE)
-		return
-	if(owner)
-		if(HAS_TRAIT(owner, TRAIT_PARALYSIS_R_LEG))
-			ADD_TRAIT(src, TRAIT_PARALYSIS, TRAIT_PARALYSIS_R_LEG)
-			RegisterSignal(owner, SIGNAL_REMOVETRAIT(TRAIT_PARALYSIS_R_LEG), PROC_REF(on_owner_paralysis_loss))
-		else
-			REMOVE_TRAIT(src, TRAIT_PARALYSIS, TRAIT_PARALYSIS_R_LEG)
-			RegisterSignal(owner, SIGNAL_ADDTRAIT(TRAIT_PARALYSIS_R_LEG), PROC_REF(on_owner_paralysis_gain))
-	if(.)
-		var/mob/living/carbon/old_owner = .
-		if(HAS_TRAIT(old_owner, TRAIT_PARALYSIS_R_LEG))
-			UnregisterSignal(old_owner, SIGNAL_REMOVETRAIT(TRAIT_PARALYSIS_R_LEG))
-			if(!owner || !HAS_TRAIT(owner, TRAIT_PARALYSIS_R_LEG))
-				REMOVE_TRAIT(src, TRAIT_PARALYSIS, TRAIT_PARALYSIS_R_LEG)
-		else
-			UnregisterSignal(old_owner, SIGNAL_ADDTRAIT(TRAIT_PARALYSIS_R_LEG))
+/obj/item/bodypart/leg/right/apply_ownership(mob/living/carbon/new_owner)
+	if(HAS_TRAIT(new_owner, TRAIT_PARALYSIS_R_LEG))
+		ADD_TRAIT(src, TRAIT_PARALYSIS, TRAIT_PARALYSIS_R_LEG)
+		RegisterSignal(new_owner, SIGNAL_REMOVETRAIT(TRAIT_PARALYSIS_R_LEG), PROC_REF(on_owner_paralysis_loss))
+	else
+		REMOVE_TRAIT(src, TRAIT_PARALYSIS, TRAIT_PARALYSIS_R_LEG)
+		RegisterSignal(new_owner, SIGNAL_ADDTRAIT(TRAIT_PARALYSIS_R_LEG), PROC_REF(on_owner_paralysis_gain))
+	..()
 
+/obj/item/bodypart/leg/right/clear_ownership(mob/living/carbon/old_owner)
+	if(HAS_TRAIT(old_owner, TRAIT_PARALYSIS_R_LEG))
+		UnregisterSignal(old_owner, SIGNAL_REMOVETRAIT(TRAIT_PARALYSIS_R_LEG))
+		REMOVE_TRAIT(src, TRAIT_PARALYSIS, TRAIT_PARALYSIS_R_LEG)
+	else
+		UnregisterSignal(old_owner, SIGNAL_ADDTRAIT(TRAIT_PARALYSIS_R_LEG))
+	..()
 
 ///Proc to react to the owner gaining the TRAIT_PARALYSIS_R_LEG trait.
 /obj/item/bodypart/leg/right/proc/on_owner_paralysis_gain(mob/living/carbon/source)
@@ -497,7 +515,6 @@
 	UnregisterSignal(owner, SIGNAL_ADDTRAIT(TRAIT_PARALYSIS_R_LEG))
 	RegisterSignal(owner, SIGNAL_REMOVETRAIT(TRAIT_PARALYSIS_R_LEG), PROC_REF(on_owner_paralysis_loss))
 
-
 ///Proc to react to the owner losing the TRAIT_PARALYSIS_R_LEG trait.
 /obj/item/bodypart/leg/right/proc/on_owner_paralysis_loss(mob/living/carbon/source)
 	SIGNAL_HANDLER

code/modules/surgery/bodyparts/species_parts/misc_bodyparts.dm

@@ -518,17 +518,16 @@
 	)
 	return ..()
 
-/obj/item/bodypart/arm/left/golem/set_owner(new_owner)
+/obj/item/bodypart/arm/left/golem/clear_ownership(mob/living/carbon/old_owner)
 	. = ..()
-	if (. == FALSE)
-		return
-	if (owner)
-		owner.AddComponentFrom(REF(src), /datum/component/shovel_hands)
-	if (isnull(.))
-		return
-	var/mob/living/carbon/old_owner = .
+
 	old_owner.RemoveComponentSource(REF(src), /datum/component/shovel_hands)
 
+/obj/item/bodypart/arm/left/golem/apply_ownership(mob/living/carbon/new_owner)
+	. = ..()
+
+	new_owner.AddComponentFrom(REF(src), /datum/component/shovel_hands)
+
 /obj/item/bodypart/arm/right/golem
 	icon = 'icons/mob/human/species/golems.dmi'
 	icon_static = 'icons/mob/human/species/golems.dmi'
@@ -552,17 +551,16 @@
 	)
 	return ..()
 
-/obj/item/bodypart/arm/right/golem/set_owner(new_owner)
+/obj/item/bodypart/arm/right/golem/clear_ownership(mob/living/carbon/old_owner)
 	. = ..()
-	if (. == FALSE)
-		return
-	if (owner)
-		owner.AddComponentFrom(REF(src), /datum/component/shovel_hands)
-	if (isnull(.))
-		return
-	var/mob/living/carbon/old_owner = .
+
 	old_owner.RemoveComponentSource(REF(src), /datum/component/shovel_hands)
 
+/obj/item/bodypart/arm/right/golem/apply_ownership(mob/living/carbon/new_owner)
+	. = ..()
+
+	new_owner.AddComponentFrom(REF(src), /datum/component/shovel_hands)
+
 /obj/item/bodypart/leg/left/golem
 	icon = 'icons/mob/human/species/golems.dmi'
 	icon_static = 'icons/mob/human/species/golems.dmi'

code/modules/surgery/organs/_organ.dm

@@ -6,6 +6,8 @@
 	throwforce = 0
 	/// The mob that owns this organ.
 	var/mob/living/carbon/owner = null
+	/// Reference to the limb we're inside of
+	var/obj/item/bodypart/bodypart_owner
 	/// The cached info about the blood this organ belongs to
 	var/list/blood_dna_info = list("Synthetic DNA" = "O+") // not every organ spawns inside a person
 	/// The body zone this organ is supposed to inhabit.
@@ -77,134 +79,16 @@ INITIALIZE_IMMEDIATE(/obj/item/organ)
 			volume = reagent_vol,\
 			after_eat = CALLBACK(src, PROC_REF(OnEatFrom)))
 
-	if(!IS_ROBOTIC_ORGAN(src))
-		add_blood_DNA(blood_dna_info)
-
-/*
- * Insert the organ into the select mob.
- *
- * receiver - the mob who will get our organ
- * special - "quick swapping" an organ out - when TRUE, the mob will be unaffected by not having that organ for the moment
- * drop_if_replaced - if there's an organ in the slot already, whether we drop it afterwards
- */
-/obj/item/organ/proc/Insert(mob/living/carbon/receiver, special = FALSE, drop_if_replaced = TRUE)
-	SHOULD_CALL_PARENT(TRUE)
-
-	if(!iscarbon(receiver) || owner == receiver)
-		return FALSE
-
-	var/obj/item/organ/replaced = receiver.get_organ_slot(slot)
-	if(replaced)
-		replaced.Remove(receiver, special = TRUE)
-		if(drop_if_replaced)
-			replaced.forceMove(get_turf(receiver))
-		else
-			qdel(replaced)
-
-	receiver.organs |= src
-	receiver.organs_slot[slot] = src
-	owner = receiver
-
-	if(!IS_ROBOTIC_ORGAN(src) && (organ_flags & ORGAN_VIRGIN))
-		blood_dna_info = receiver.get_blood_dna_list()
-		// need to remove the synethic blood DNA that is initialized
-		// wash also adds the blood dna again
-		wash(CLEAN_TYPE_BLOOD)
-		organ_flags &= ~ORGAN_VIRGIN
-
-
-	// Apply unique side-effects. Return value does not matter.
-	on_insert(receiver, special)
-
-	return TRUE
-
-/// Called after the organ is inserted into a mob.
-/// Adds Traits, Actions, and Status Effects on the mob in which the organ is impanted.
-/// Override this proc to create unique side-effects for inserting your organ. Must be called by overrides.
-/obj/item/organ/proc/on_insert(mob/living/carbon/organ_owner, special)
-	SHOULD_CALL_PARENT(TRUE)
-
-	moveToNullspace()
-
-	for(var/trait in organ_traits)
-		ADD_TRAIT(organ_owner, trait, REF(src))
-
-	for(var/datum/action/action as anything in actions)
-		action.Grant(organ_owner)
-
-	for(var/datum/status_effect/effect as anything in organ_effects)
-		organ_owner.apply_status_effect(effect, type)
-
-	RegisterSignal(owner, COMSIG_ATOM_EXAMINE, PROC_REF(on_owner_examine))
-	SEND_SIGNAL(src, COMSIG_ORGAN_IMPLANTED, organ_owner)
-	SEND_SIGNAL(organ_owner, COMSIG_CARBON_GAIN_ORGAN, src, special)
-
-/*
- * Remove the organ from the select mob.
- *
- * * organ_owner - the mob who owns our organ, that we're removing the organ from.
- * * special - "quick swapping" an organ out - when TRUE, the mob will be unaffected by not having that organ for the moment
- */
-/obj/item/organ/proc/Remove(mob/living/carbon/organ_owner, special = FALSE)
-	SHOULD_CALL_PARENT(TRUE)
-
-	organ_owner.organs -= src
-	if(organ_owner.organs_slot[slot] == src)
-		organ_owner.organs_slot.Remove(slot)
-
-	owner = null
-
-	// Apply or reset unique side-effects. Return value does not matter.
-	on_remove(organ_owner, special)
-
-	return TRUE
-
-/// Called after the organ is removed from a mob.
-/// Removes Traits, Actions, and Status Effects on the mob in which the organ was impanted.
-/// Override this proc to create unique side-effects for removing your organ. Must be called by overrides.
-/obj/item/organ/proc/on_remove(mob/living/carbon/organ_owner, special)
-	SHOULD_CALL_PARENT(TRUE)
-
-	if(!iscarbon(organ_owner))
-		stack_trace("Organ removal should not be happening on non carbon mobs: [organ_owner]")
-
-	for(var/trait in organ_traits)
-		REMOVE_TRAIT(organ_owner, trait, REF(src))
-
-	for(var/datum/action/action as anything in actions)
-		action.Remove(organ_owner)
-
-	for(var/datum/status_effect/effect as anything in organ_effects)
-		organ_owner.remove_status_effect(effect, type)
-
-	UnregisterSignal(organ_owner, COMSIG_ATOM_EXAMINE)
-	SEND_SIGNAL(src, COMSIG_ORGAN_REMOVED, organ_owner)
-	SEND_SIGNAL(organ_owner, COMSIG_CARBON_LOSE_ORGAN, src, special)
-
-	// We don't need to readd things to the organ if it's getting deleted
-	if(QDELING(src))
-		return
-
-	if(!IS_ROBOTIC_ORGAN(src) && !(item_flags & NO_BLOOD_ON_ITEM))
-		AddElement(/datum/element/decal/blood)
-
-	var/list/diseases = organ_owner.get_static_viruses()
-	if(!LAZYLEN(diseases))
-		return
-
-	var/list/datum/disease/diseases_to_add = list()
-	for(var/datum/disease/disease as anything in diseases)
-		// robotic organs are immune to disease unless 'inorganic biology' symptom is present
-		if(IS_ROBOTIC_ORGAN(src) && !(disease.infectable_biotypes & MOB_ROBOTIC))
-			continue
-
-		// admin or special viruses that should not be reproduced
-		if(disease.spread_flags & (DISEASE_SPREAD_SPECIAL | DISEASE_SPREAD_NON_CONTAGIOUS))
-			continue
-
-		diseases_to_add += disease
-	if(LAZYLEN(diseases_to_add))
-		AddComponent(/datum/component/infective, diseases_to_add)
+/obj/item/organ/Destroy()
+	if(bodypart_owner && !owner && !QDELETED(bodypart_owner))
+		bodypart_remove(bodypart_owner)
+	else if(owner)
+		// The special flag is important, because otherwise mobs can die
+		// while undergoing transformation into different mobs.
+		Remove(owner, special=TRUE)
+	else
+		STOP_PROCESSING(SSobj, src)
+	return ..()
 
 /// Add a Trait to an organ that it will give its owner.
 /obj/item/organ/proc/add_organ_trait(trait)
@@ -241,15 +125,6 @@ INITIALIZE_IMMEDIATE(/obj/item/organ)
 /obj/item/organ/proc/on_find(mob/living/finder)
 	return
 
-/**
- * Proc that gets called when the organ is surgically removed by someone, can be used for special effects
- * Currently only used so surplus organs can explode when surgically removed.
- */
-/obj/item/organ/proc/on_surgical_removal(mob/living/user, mob/living/carbon/old_owner, target_zone, obj/item/tool)
-	SHOULD_CALL_PARENT(TRUE)
-	SEND_SIGNAL(src, COMSIG_ORGAN_SURGICALLY_REMOVED, user, old_owner, target_zone, tool)
-	RemoveElement(/datum/element/decal/blood)
-
 /obj/item/organ/wash(clean_types)
 	. = ..()
 
@@ -452,4 +327,4 @@ INITIALIZE_IMMEDIATE(/obj/item/organ)
 
 /// Tries to replace the existing organ on the passed mob with this one, with special handling for replacing a brain without ghosting target
 /obj/item/organ/proc/replace_into(mob/living/carbon/new_owner)
-	return Insert(new_owner, special = TRUE, drop_if_replaced = FALSE)
+	return Insert(new_owner, special = TRUE, movement_flags = DELETE_IF_REPLACED)

code/modules/surgery/organs/external/_external_organ.dm

@@ -12,8 +12,6 @@
 
 	///The overlay datum that actually draws stuff on the limb
 	var/datum/bodypart_overlay/mutant/bodypart_overlay
-	///Reference to the limb we're inside of
-	var/obj/item/bodypart/ownerlimb
 	///If not null, overrides the appearance with this sprite accessory datum
 	var/sprite_accessory_override
 
@@ -25,7 +23,7 @@
 	///Set to EXTERNAL_BEHIND, EXTERNAL_FRONT or EXTERNAL_ADJACENT if you want to draw one of those layers as the object sprite. FALSE to use your own
 	///This will not work if it doesn't have a limb to generate it's icon with
 	var/use_mob_sprite_as_obj_sprite = FALSE
-	///Does this organ have any bodytypes to pass to it's ownerlimb?
+	///Does this organ have any bodytypes to pass to it's bodypart_owner?
 	var/external_bodytypes = NONE
 	///Which flags does a 'modification tool' need to have to restyle us, if it all possible (located in code/_DEFINES/mobs)
 	var/restyle_flags = NONE
@@ -55,23 +53,10 @@
 	if(restyle_flags)
 		RegisterSignal(src, COMSIG_ATOM_RESTYLE, PROC_REF(on_attempt_feature_restyle))
 
-/obj/item/organ/external/Destroy()
-	if(owner)
-		Remove(owner, special=TRUE)
-	else if(ownerlimb)
-		remove_from_limb()
-
-	return ..()
-
-/obj/item/organ/external/Insert(mob/living/carbon/receiver, special, drop_if_replaced)
+/obj/item/organ/external/mob_insert(mob/living/carbon/receiver, special, movement_flags)
 	if(!should_external_organ_apply_to(type, receiver))
 		stack_trace("adding a [type] to a [receiver.type] when it shouldn't be!")
 
-	var/obj/item/bodypart/limb = receiver.get_bodypart(deprecise_zone(zone))
-
-	if(!limb)
-		return FALSE
-
 	. = ..()
 
 	if(!.)
@@ -84,54 +69,28 @@
 		bodypart_overlay.set_appearance_from_name(feature_name)
 		bodypart_overlay.imprint_on_next_insertion = FALSE
 
-	ownerlimb = limb
-	add_to_limb(ownerlimb)
-
 	if(external_bodytypes)
 		receiver.synchronize_bodytypes()
 
 	receiver.update_body_parts()
 
-/obj/item/organ/external/Remove(mob/living/carbon/organ_owner, special, moving)
-	. = ..()
-
-	if(ownerlimb)
-		remove_from_limb()
-		if(!moving && use_mob_sprite_as_obj_sprite) //so we're being taken out and dropped
-			update_appearance(UPDATE_OVERLAYS)
-
-	if(organ_owner)
+/obj/item/organ/external/mob_remove(mob/living/carbon/organ_owner, special, moving)
+	if(!special)
+		organ_owner.synchronize_bodytypes()
 		organ_owner.update_body_parts()
-
-
-/obj/item/organ/external/on_remove(mob/living/carbon/organ_owner, special)
-	. = ..()
-	color = bodypart_overlay.draw_color // so a pink felinid doesn't drop a gray tail
-
-///Transfers the organ to the limb, and to the limb's owner, if it has one.
-/obj/item/organ/external/transfer_to_limb(obj/item/bodypart/bodypart, mob/living/carbon/bodypart_owner)
-	if(owner)
-		Remove(owner, moving = TRUE)
-	else if(ownerlimb)
-		remove_from_limb()
-
-	if(bodypart_owner)
-		Insert(bodypart_owner, TRUE)
-	else
-		add_to_limb(bodypart)
-
-/obj/item/organ/external/add_to_limb(obj/item/bodypart/bodypart)
-	bodypart.external_organs += src
-	ownerlimb = bodypart
-	ownerlimb.add_bodypart_overlay(bodypart_overlay)
 	return ..()
 
-/obj/item/organ/external/remove_from_limb()
-	ownerlimb.external_organs -= src
-	ownerlimb.remove_bodypart_overlay(bodypart_overlay)
-	if(ownerlimb.owner && external_bodytypes)
-		ownerlimb.owner.synchronize_bodytypes()
-	ownerlimb = null
+/obj/item/organ/external/on_bodypart_insert(obj/item/bodypart/bodypart)
+	bodypart.add_bodypart_overlay(bodypart_overlay)
+	return ..()
+
+/obj/item/organ/external/on_bodypart_remove(obj/item/bodypart/bodypart)
+	bodypart.remove_bodypart_overlay(bodypart_overlay)
+
+	if(use_mob_sprite_as_obj_sprite)
+		update_appearance(UPDATE_OVERLAYS)
+
+	color = bodypart_overlay.draw_color // so a pink felinid doesn't drop a gray tail
 	return ..()
 
 /proc/should_external_organ_apply_to(obj/item/organ/external/organpath, mob/living/carbon/target)
@@ -165,8 +124,8 @@
 
 	if(owner) //are we in a person?
 		owner.update_body_parts()
-	else if(ownerlimb) //are we in a limb?
-		ownerlimb.update_icon_dropped()
+	else if(bodypart_owner) //are we in a limb?
+		bodypart_owner.update_icon_dropped()
 	//else if(use_mob_sprite_as_obj_sprite) //are we out in the world, unprotected by flesh?
 
 /obj/item/organ/external/on_life(seconds_per_tick, times_fired)
@@ -181,7 +140,7 @@
 	//Build the mob sprite and use it as our overlay
 	for(var/external_layer in bodypart_overlay.all_layers)
 		if(bodypart_overlay.layers & external_layer)
-			. += bodypart_overlay.get_overlay(external_layer, ownerlimb)
+			. += bodypart_overlay.get_overlay(external_layer, bodypart_owner)
 
 ///The horns of a lizard!
 /obj/item/organ/external/horns
@@ -287,16 +246,17 @@
 	///Store our old datum here for if our antennae are healed
 	var/original_sprite_datum
 
-/obj/item/organ/external/antennae/Insert(mob/living/carbon/receiver, special, drop_if_replaced)
+/obj/item/organ/external/antennae/Insert(mob/living/carbon/receiver, special, movement_flags)
 	. = ..()
 	if(!.)
 		return
 	RegisterSignal(receiver, COMSIG_HUMAN_BURNING, PROC_REF(try_burn_antennae))
 	RegisterSignal(receiver, COMSIG_LIVING_POST_FULLY_HEAL, PROC_REF(heal_antennae))
 
-/obj/item/organ/external/antennae/Remove(mob/living/carbon/organ_owner, special, moving)
+/obj/item/organ/external/antennae/Remove(mob/living/carbon/organ_owner, special, movement_flags)
 	. = ..()
-	UnregisterSignal(organ_owner, list(COMSIG_HUMAN_BURNING, COMSIG_LIVING_POST_FULLY_HEAL))
+	if(organ_owner)
+		UnregisterSignal(organ_owner, list(COMSIG_HUMAN_BURNING, COMSIG_LIVING_POST_FULLY_HEAL))
 
 ///check if our antennae can burn off ;_;
 /obj/item/organ/external/antennae/proc/try_burn_antennae(mob/living/carbon/human/human)

code/modules/surgery/organs/external/restyling.dm

@@ -31,7 +31,7 @@
 ///Asks the external organs inside the limb if they can restyle
 /obj/item/bodypart/proc/attempt_feature_restyle(atom/source, mob/living/trimmer, atom/movable/original_target, body_zone, restyle_type, style_speed)
 	var/list/valid_features = list()
-	for(var/obj/item/organ/external/feature in external_organs)
+	for(var/obj/item/organ/external/feature in contents)
 		if(feature.restyle_flags & restyle_type)
 			valid_features.Add(feature)
 

code/modules/surgery/organs/external/spines.dm

@@ -17,13 +17,13 @@
 	///A two-way reference between the tail and the spines because of wagging sprites. Bruh.
 	var/obj/item/organ/external/tail/lizard/paired_tail
 
-/obj/item/organ/external/spines/Insert(mob/living/carbon/receiver, special, drop_if_replaced)
+/obj/item/organ/external/spines/Insert(mob/living/carbon/receiver, special, movement_flags)
 	. = ..()
 	if(.)
 		paired_tail = locate(/obj/item/organ/external/tail/lizard) in receiver.organs //We want specifically a lizard tail, so we don't use the slot.
 		paired_tail?.paired_spines = src
 
-/obj/item/organ/external/spines/Remove(mob/living/carbon/organ_owner, special, moving)
+/obj/item/organ/external/spines/Remove(mob/living/carbon/organ_owner, special, movement_flags)
 	. = ..()
 	if(paired_tail)
 		paired_tail.paired_spines = null

code/modules/surgery/organs/external/tails.dm

@@ -18,7 +18,7 @@
 	///The original owner of this tail
 	var/original_owner //Yay, snowflake code!
 
-/obj/item/organ/external/tail/Insert(mob/living/carbon/receiver, special, drop_if_replaced)
+/obj/item/organ/external/tail/Insert(mob/living/carbon/receiver, special, movement_flags)
 	. = ..()
 	if(.)
 		RegisterSignal(receiver, COMSIG_ORGAN_WAG_TAIL, PROC_REF(wag))
@@ -32,15 +32,12 @@
 		else if(type in receiver.dna.species.external_organs)
 			receiver.add_mood_event("wrong_tail_regained", /datum/mood_event/tail_regained_wrong)
 
-/obj/item/organ/external/tail/Remove(mob/living/carbon/organ_owner, special, moving)
+/obj/item/organ/external/tail/on_mob_remove(mob/living/carbon/organ_owner, special)
+	. = ..()
+
 	if(wag_flags & WAG_WAGGING)
 		wag(organ_owner, start = FALSE)
 
-	return ..()
-
-/obj/item/organ/external/tail/on_remove(mob/living/carbon/organ_owner, special)
-	. = ..()
-
 	UnregisterSignal(organ_owner, COMSIG_ORGAN_WAG_TAIL)
 
 	if(type in organ_owner.dna.species.external_organs)
@@ -136,13 +133,13 @@
 	///A reference to the paired_spines, since for some fucking reason tail spines are tied to the spines themselves.
 	var/obj/item/organ/external/spines/paired_spines
 
-/obj/item/organ/external/tail/lizard/Insert(mob/living/carbon/receiver, special, drop_if_replaced)
+/obj/item/organ/external/tail/lizard/Insert(mob/living/carbon/receiver, special, movement_flags)
 	. = ..()
 	if(.)
-		paired_spines = ownerlimb.owner.get_organ_slot(ORGAN_SLOT_EXTERNAL_SPINES)
+		paired_spines = bodypart_owner.owner.get_organ_slot(ORGAN_SLOT_EXTERNAL_SPINES)
 		paired_spines?.paired_tail = src
 
-/obj/item/organ/external/tail/lizard/Remove(mob/living/carbon/organ_owner, special, moving)
+/obj/item/organ/external/tail/lizard/Remove(mob/living/carbon/organ_owner, special, movement_flags)
 	. = ..()
 	if(paired_spines)
 		paired_spines.paired_tail = null

code/modules/surgery/organs/external/wings/functional_wings.dm

@@ -29,13 +29,13 @@
 	// grind_results = list(/datum/reagent/flightpotion = 5)
 	food_reagents = list(/datum/reagent/flightpotion = 5)
 
-/obj/item/organ/external/wings/functional/Insert(mob/living/carbon/receiver, special, drop_if_replaced)
+/obj/item/organ/external/wings/functional/Insert(mob/living/carbon/receiver, special, movement_flags)
 	. = ..()
 	if(. && isnull(fly))
 		fly = new
 		fly.Grant(receiver)
 
-/obj/item/organ/external/wings/functional/Remove(mob/living/carbon/organ_owner, special, moving)
+/obj/item/organ/external/wings/functional/Remove(mob/living/carbon/organ_owner, special, movement_flags)
 	. = ..()
 
 	fly.Remove(organ_owner)

code/modules/surgery/organs/external/wings/moth_wings.dm

@@ -14,13 +14,13 @@
 	///Store our old datum here for if our burned wings are healed
 	var/original_sprite_datum
 
-/obj/item/organ/external/wings/moth/on_insert(mob/living/carbon/receiver)
+/obj/item/organ/external/wings/moth/on_mob_insert(mob/living/carbon/receiver)
 	. = ..()
 	RegisterSignal(receiver, COMSIG_HUMAN_BURNING, PROC_REF(try_burn_wings))
 	RegisterSignal(receiver, COMSIG_LIVING_POST_FULLY_HEAL, PROC_REF(heal_wings))
 	RegisterSignal(receiver, COMSIG_MOVABLE_PRE_MOVE, PROC_REF(update_float_move))
 
-/obj/item/organ/external/wings/moth/on_remove(mob/living/carbon/organ_owner)
+/obj/item/organ/external/wings/moth/on_mob_remove(mob/living/carbon/organ_owner)
 	. = ..()
 	UnregisterSignal(organ_owner, list(COMSIG_HUMAN_BURNING, COMSIG_LIVING_POST_FULLY_HEAL, COMSIG_MOVABLE_PRE_MOVE))
 	REMOVE_TRAIT(organ_owner, TRAIT_FREE_FLOAT_MOVEMENT, REF(src))

code/modules/surgery/organs/internal/_internal_organ.dm

@@ -5,19 +5,8 @@
 	. = ..()
 	START_PROCESSING(SSobj, src)
 
-/obj/item/organ/internal/Destroy()
-	if(owner)
-		// The special flag is important, because otherwise mobs can die
-		// while undergoing transformation into different mobs.
-		Remove(owner, special=TRUE)
-	else
-		STOP_PROCESSING(SSobj, src)
-	return ..()
-
-/obj/item/organ/internal/Insert(mob/living/carbon/receiver, special = FALSE, drop_if_replaced = TRUE)
+/obj/item/organ/internal/on_mob_insert(mob/living/carbon/organ_owner, special, movement_flags)
 	. = ..()
-	if(!. || !owner)
-		return
 
 	// organs_slot must ALWAYS be ordered in the same way as organ_process_order
 	// Otherwise life processing breaks down
@@ -25,18 +14,16 @@
 
 	STOP_PROCESSING(SSobj, src)
 
-/obj/item/organ/internal/Remove(mob/living/carbon/organ_owner, special = FALSE)
+/obj/item/organ/internal/on_mob_remove(mob/living/carbon/organ_owner, special = FALSE)
 	. = ..()
 
-	if(organ_owner)
-		if((organ_flags & ORGAN_VITAL) && !special && !(organ_owner.status_flags & GODMODE))
-			if(organ_owner.stat != DEAD)
-				organ_owner.investigate_log("has been killed by losing a vital organ ([src]).", INVESTIGATE_DEATHS)
-			organ_owner.death()
+	if((organ_flags & ORGAN_VITAL) && !special && !(organ_owner.status_flags & GODMODE))
+		if(organ_owner.stat != DEAD)
+			organ_owner.investigate_log("has been killed by losing a vital organ ([src]).", INVESTIGATE_DEATHS)
+		organ_owner.death()
 
 	START_PROCESSING(SSobj, src)
 
-
 /obj/item/organ/internal/process(seconds_per_tick, times_fired)
 	on_death(seconds_per_tick, times_fired) //Kinda hate doing it like this, but I really don't want to call process directly.
 

code/modules/surgery/organs/internal/appendix/_appendix.dm

@@ -76,12 +76,12 @@
 /obj/item/organ/internal/appendix/get_availability(datum/species/owner_species, mob/living/owner_mob)
 	return owner_species.mutantappendix
 
-/obj/item/organ/internal/appendix/on_remove(mob/living/carbon/organ_owner)
+/obj/item/organ/internal/appendix/on_mob_remove(mob/living/carbon/organ_owner)
 	. = ..()
 	REMOVE_TRAIT(organ_owner, TRAIT_DISEASELIKE_SEVERITY_MEDIUM, type)
 	organ_owner.med_hud_set_status()
 
-/obj/item/organ/internal/appendix/on_insert(mob/living/carbon/organ_owner)
+/obj/item/organ/internal/appendix/on_mob_insert(mob/living/carbon/organ_owner)
 	. = ..()
 	if(inflamation_stage)
 		ADD_TRAIT(organ_owner, TRAIT_DISEASELIKE_SEVERITY_MEDIUM, type)

code/modules/surgery/organs/internal/appendix/appendix_golem.dm

@@ -12,7 +12,7 @@
 	. = ..()
 	smelter = new(src)
 
-/obj/item/organ/internal/appendix/golem/on_insert(mob/living/carbon/organ_owner)
+/obj/item/organ/internal/appendix/golem/on_mob_insert(mob/living/carbon/organ_owner)
 	. = ..()
 	RegisterSignal(owner, COMSIG_MOVABLE_MOVED, PROC_REF(check_for_lava))
 
@@ -25,7 +25,7 @@
 	if (smelter.owner != owner)
 		smelter.Grant(owner)
 
-/obj/item/organ/internal/appendix/golem/on_remove(mob/living/carbon/organ_owner)
+/obj/item/organ/internal/appendix/golem/on_mob_remove(mob/living/carbon/organ_owner)
 	UnregisterSignal(organ_owner, COMSIG_MOVABLE_MOVED)
 	smelter?.Remove(organ_owner) // Might have been deleted by Destroy already
 	return ..()

code/modules/surgery/organs/internal/cyberimp/augments_arms.dm

@@ -76,7 +76,7 @@
 	to_chat(user, span_notice("You modify [src] to be installed on the [zone == BODY_ZONE_R_ARM ? "right" : "left"] arm."))
 	update_appearance()
 
-/obj/item/organ/internal/cyberimp/arm/on_insert(mob/living/carbon/arm_owner)
+/obj/item/organ/internal/cyberimp/arm/on_mob_insert(mob/living/carbon/arm_owner)
 	. = ..()
 	var/side = zone == BODY_ZONE_R_ARM? RIGHT_HANDS : LEFT_HANDS
 	hand = arm_owner.hand_bodyparts[side]
@@ -84,7 +84,7 @@
 		RegisterSignal(hand, COMSIG_ITEM_ATTACK_SELF, PROC_REF(on_item_attack_self)) //If the limb gets an attack-self, open the menu. Only happens when hand is empty
 		RegisterSignal(arm_owner, COMSIG_KB_MOB_DROPITEM_DOWN, PROC_REF(dropkey)) //We're nodrop, but we'll watch for the drop hotkey anyway and then stow if possible.
 
-/obj/item/organ/internal/cyberimp/arm/on_remove(mob/living/carbon/arm_owner)
+/obj/item/organ/internal/cyberimp/arm/on_mob_remove(mob/living/carbon/arm_owner)
 	. = ..()
 	Retract()
 	if(hand)
@@ -378,14 +378,14 @@
 	///How long will the implant malfunction if it is EMP'd
 	var/emp_base_duration = 9 SECONDS
 
-/obj/item/organ/internal/cyberimp/arm/muscle/Insert(mob/living/carbon/receiver, special = FALSE, drop_if_replaced = TRUE)
+/obj/item/organ/internal/cyberimp/arm/muscle/on_mob_insert(mob/living/carbon/arm_owner)
 	. = ..()
-	if(ishuman(receiver)) //Sorry, only humans
-		RegisterSignal(receiver, COMSIG_LIVING_EARLY_UNARMED_ATTACK, PROC_REF(on_attack_hand))
+	if(ishuman(arm_owner)) //Sorry, only humans
+		RegisterSignal(arm_owner, COMSIG_LIVING_EARLY_UNARMED_ATTACK, PROC_REF(on_attack_hand))
 
-/obj/item/organ/internal/cyberimp/arm/muscle/Remove(mob/living/carbon/implant_owner, special = 0)
+/obj/item/organ/internal/cyberimp/arm/muscle/on_mob_remove(mob/living/carbon/arm_owner)
 	. = ..()
-	UnregisterSignal(implant_owner, COMSIG_LIVING_EARLY_UNARMED_ATTACK)
+	UnregisterSignal(arm_owner, COMSIG_LIVING_EARLY_UNARMED_ATTACK)
 
 /obj/item/organ/internal/cyberimp/arm/muscle/emp_act(severity)
 	. = ..()

code/modules/surgery/organs/internal/cyberimp/augments_chest.dm

@@ -182,7 +182,7 @@
 		/datum/effect_system/trail_follow/ion \
 	)
 
-/obj/item/organ/internal/cyberimp/chest/thrusters/Remove(mob/living/carbon/thruster_owner, special = 0)
+/obj/item/organ/internal/cyberimp/chest/thrusters/Remove(mob/living/carbon/thruster_owner, special, movement_flags)
 	if(on)
 		deactivate(silent = TRUE)
 	..()

code/modules/surgery/organs/internal/cyberimp/augments_eyes.dm

@@ -31,7 +31,7 @@
 			hud.show_to(eye_owner)
 		toggled_on = TRUE
 
-/obj/item/organ/internal/cyberimp/eyes/hud/Insert(mob/living/carbon/eye_owner, special = FALSE, drop_if_replaced = TRUE)
+/obj/item/organ/internal/cyberimp/eyes/hud/Insert(mob/living/carbon/eye_owner, special = FALSE, movement_flags)
 	. = ..()
 	if(!.)
 		return
@@ -42,7 +42,7 @@
 		ADD_TRAIT(eye_owner, HUD_trait, ORGAN_TRAIT)
 	toggled_on = TRUE
 
-/obj/item/organ/internal/cyberimp/eyes/hud/Remove(mob/living/carbon/eye_owner, special = FALSE)
+/obj/item/organ/internal/cyberimp/eyes/hud/Remove(mob/living/carbon/eye_owner, special, movement_flags)
 	. = ..()
 	if(HUD_type)
 		var/datum/atom_hud/hud = GLOB.huds[HUD_type]

code/modules/surgery/organs/internal/cyberimp/augments_internal.dm

@@ -87,7 +87,7 @@
 	stored_items = list()
 
 
-/obj/item/organ/internal/cyberimp/brain/anti_drop/Remove(mob/living/carbon/implant_owner, special = 0)
+/obj/item/organ/internal/cyberimp/brain/anti_drop/Remove(mob/living/carbon/implant_owner, special, movement_flags)
 	if(active)
 		ui_action_click()
 	..()
@@ -113,11 +113,11 @@
 
 	var/stun_cap_amount = 40
 
-/obj/item/organ/internal/cyberimp/brain/anti_stun/on_remove(mob/living/carbon/implant_owner)
+/obj/item/organ/internal/cyberimp/brain/anti_stun/on_mob_remove(mob/living/carbon/implant_owner)
 	. = ..()
 	UnregisterSignal(implant_owner, signalCache)
 
-/obj/item/organ/internal/cyberimp/brain/anti_stun/on_insert(mob/living/carbon/receiver)
+/obj/item/organ/internal/cyberimp/brain/anti_stun/on_mob_insert(mob/living/carbon/receiver)
 	. = ..()
 	RegisterSignals(receiver, signalCache, PROC_REF(on_signal))
 

code/modules/surgery/organs/internal/ears/_ears.dm

@@ -68,7 +68,7 @@
 	visual = TRUE
 	damage_multiplier = 2
 
-/obj/item/organ/internal/ears/cat/on_insert(mob/living/carbon/human/ear_owner)
+/obj/item/organ/internal/ears/cat/on_mob_insert(mob/living/carbon/human/ear_owner)
 	. = ..()
 	if(istype(ear_owner) && ear_owner.dna)
 		color = ear_owner.hair_color
@@ -76,7 +76,7 @@
 		ear_owner.dna.update_uf_block(DNA_EARS_BLOCK)
 		ear_owner.update_body()
 
-/obj/item/organ/internal/ears/cat/on_remove(mob/living/carbon/human/ear_owner)
+/obj/item/organ/internal/ears/cat/on_mob_remove(mob/living/carbon/human/ear_owner)
 	. = ..()
 	if(istype(ear_owner) && ear_owner.dna)
 		color = ear_owner.hair_color
@@ -87,13 +87,13 @@
 	name = "penguin ears"
 	desc = "The source of a penguin's happy feet."
 
-/obj/item/organ/internal/ears/penguin/on_insert(mob/living/carbon/human/ear_owner)
+/obj/item/organ/internal/ears/penguin/on_mob_insert(mob/living/carbon/human/ear_owner)
 	. = ..()
 	if(istype(ear_owner))
 		to_chat(ear_owner, span_notice("You suddenly feel like you've lost your balance."))
 		ear_owner.AddElement(/datum/element/waddling)
 
-/obj/item/organ/internal/ears/penguin/on_remove(mob/living/carbon/human/ear_owner)
+/obj/item/organ/internal/ears/penguin/on_mob_remove(mob/living/carbon/human/ear_owner)
 	. = ..()
 	if(istype(ear_owner))
 		to_chat(ear_owner, span_notice("Your sense of balance comes back to you."))
@@ -122,11 +122,11 @@
 
 // The original idea was to use signals to do this not traits. Unfortunately, the star effect used for whispers applies before any relevant signals
 // This seems like the least invasive solution
-/obj/item/organ/internal/ears/cybernetic/whisper/on_insert(mob/living/carbon/ear_owner)
+/obj/item/organ/internal/ears/cybernetic/whisper/on_mob_insert(mob/living/carbon/ear_owner)
 	. = ..()
 	ADD_TRAIT(ear_owner, TRAIT_GOOD_HEARING, ORGAN_TRAIT)
 
-/obj/item/organ/internal/ears/cybernetic/whisper/on_remove(mob/living/carbon/ear_owner)
+/obj/item/organ/internal/ears/cybernetic/whisper/on_mob_remove(mob/living/carbon/ear_owner)
 	. = ..()
 	REMOVE_TRAIT(ear_owner, TRAIT_GOOD_HEARING, ORGAN_TRAIT)
 
@@ -138,11 +138,11 @@
 	// Same sensitivity as felinid ears
 	damage_multiplier = 2
 
-/obj/item/organ/internal/ears/cybernetic/xray/on_insert(mob/living/carbon/ear_owner)
+/obj/item/organ/internal/ears/cybernetic/xray/on_mob_insert(mob/living/carbon/ear_owner)
 	. = ..()
 	ADD_TRAIT(ear_owner, TRAIT_XRAY_HEARING, ORGAN_TRAIT)
 
-/obj/item/organ/internal/ears/cybernetic/xray/on_remove(mob/living/carbon/ear_owner)
+/obj/item/organ/internal/ears/cybernetic/xray/on_mob_remove(mob/living/carbon/ear_owner)
 	. = ..()
 	REMOVE_TRAIT(ear_owner, TRAIT_XRAY_HEARING, ORGAN_TRAIT)
 

code/modules/surgery/organs/internal/eyes/_eyes.dm

@@ -52,7 +52,7 @@
 	/// Native FOV that will be applied if a config is enabled
 	var/native_fov = FOV_90_DEGREES
 
-/obj/item/organ/internal/eyes/Insert(mob/living/carbon/eye_recipient, special = FALSE, drop_if_replaced = FALSE)
+/obj/item/organ/internal/eyes/Insert(mob/living/carbon/eye_recipient, special = FALSE, movement_flags = DELETE_IF_REPLACED)
 	// If we don't do this before everything else, heterochromia will be reset leading to eye_color_right no longer being accurate
 	if(ishuman(eye_recipient))
 		var/mob/living/carbon/human/human_recipient = eye_recipient
@@ -94,7 +94,7 @@
 	if(call_update)
 		affected_human.update_body()
 
-/obj/item/organ/internal/eyes/Remove(mob/living/carbon/eye_owner, special = FALSE)
+/obj/item/organ/internal/eyes/Remove(mob/living/carbon/eye_owner, special, movement_flags)
 	. = ..()
 	if(ishuman(eye_owner))
 		var/mob/living/carbon/human/human_owner = eye_owner
@@ -104,7 +104,8 @@
 			human_owner.eye_color_right = old_eye_color_right
 		if(native_fov)
 			eye_owner.remove_fov_trait(type)
-		human_owner.update_body()
+		if(!special)
+			human_owner.update_body()
 
 	// Cure blindness from eye damage
 	eye_owner.cure_blind(EYE_DAMAGE)
@@ -327,11 +328,11 @@
 	eye_color_right = "000"
 	sight_flags = SEE_MOBS | SEE_OBJS | SEE_TURFS
 
-/obj/item/organ/internal/eyes/robotic/xray/on_insert(mob/living/carbon/eye_owner)
+/obj/item/organ/internal/eyes/robotic/xray/on_mob_insert(mob/living/carbon/eye_owner)
 	. = ..()
 	ADD_TRAIT(eye_owner, TRAIT_XRAY_VISION, ORGAN_TRAIT)
 
-/obj/item/organ/internal/eyes/robotic/xray/on_remove(mob/living/carbon/eye_owner)
+/obj/item/organ/internal/eyes/robotic/xray/on_mob_remove(mob/living/carbon/eye_owner)
 	. = ..()
 	REMOVE_TRAIT(eye_owner, TRAIT_XRAY_VISION, ORGAN_TRAIT)
 
@@ -359,7 +360,7 @@
 /obj/item/organ/internal/eyes/robotic/flashlight/emp_act(severity)
 	return
 
-/obj/item/organ/internal/eyes/robotic/flashlight/on_insert(mob/living/carbon/victim)
+/obj/item/organ/internal/eyes/robotic/flashlight/on_mob_insert(mob/living/carbon/victim)
 	. = ..()
 	if(!eye)
 		eye = new /obj/item/flashlight/eyelight()
@@ -368,7 +369,7 @@
 	eye.update_brightness(victim)
 	victim.become_blind(FLASHLIGHT_EYES)
 
-/obj/item/organ/internal/eyes/robotic/flashlight/on_remove(mob/living/carbon/victim)
+/obj/item/organ/internal/eyes/robotic/flashlight/on_mob_remove(mob/living/carbon/victim)
 	. = ..()
 	eye.set_light_on(FALSE)
 	eye.update_brightness(victim)
@@ -425,18 +426,18 @@
 	deactivate(close_ui = TRUE)
 
 /// Set the initial color of the eyes on insert to be the mob's previous eye color.
-/obj/item/organ/internal/eyes/robotic/glow/Insert(mob/living/carbon/eye_recipient, special = FALSE, drop_if_replaced = FALSE)
+/obj/item/organ/internal/eyes/robotic/glow/Insert(mob/living/carbon/eye_recipient, special = FALSE, movement_flags = DELETE_IF_REPLACED)
 	. = ..()
 	left_eye_color_string = old_eye_color_left
 	right_eye_color_string = old_eye_color_right
 	update_mob_eye_color(eye_recipient)
 
-/obj/item/organ/internal/eyes/robotic/glow/on_insert(mob/living/carbon/eye_recipient)
+/obj/item/organ/internal/eyes/robotic/glow/on_mob_insert(mob/living/carbon/eye_recipient)
 	. = ..()
 	deactivate(close_ui = TRUE)
 	eye.forceMove(eye_recipient)
 
-/obj/item/organ/internal/eyes/robotic/glow/on_remove(mob/living/carbon/eye_owner)
+/obj/item/organ/internal/eyes/robotic/glow/on_mob_remove(mob/living/carbon/eye_owner)
 	deactivate(eye_owner, close_ui = TRUE)
 	if(!QDELETED(eye))
 		eye.forceMove(src)
@@ -723,7 +724,7 @@
 	high_light_cutoff = list(30, 35, 50)
 	var/obj/item/flashlight/eyelight/adapted/adapt_light
 
-/obj/item/organ/internal/eyes/night_vision/maintenance_adapted/on_insert(mob/living/carbon/eye_owner)
+/obj/item/organ/internal/eyes/night_vision/maintenance_adapted/on_mob_insert(mob/living/carbon/eye_owner)
 	. = ..()
 	//add lighting
 	if(!adapt_light)
@@ -742,7 +743,7 @@
 		apply_organ_damage(-10) //heal quickly
 	. = ..()
 
-/obj/item/organ/internal/eyes/night_vision/maintenance_adapted/Remove(mob/living/carbon/unadapted, special = FALSE)
+/obj/item/organ/internal/eyes/night_vision/maintenance_adapted/on_mob_remove(mob/living/carbon/unadapted, special = FALSE)
 	//remove lighting
 	adapt_light.set_light_on(FALSE)
 	adapt_light.update_brightness(unadapted)

code/modules/surgery/organs/internal/heart/_heart.dm

@@ -33,7 +33,7 @@
 	. = ..()
 	icon_state = "[base_icon_state]-[beating ? "on" : "off"]"
 
-/obj/item/organ/internal/heart/Remove(mob/living/carbon/heartless, special = 0)
+/obj/item/organ/internal/heart/Remove(mob/living/carbon/heartless, special, movement_flags)
 	. = ..()
 	if(!special)
 		addtimer(CALLBACK(src, PROC_REF(stop_if_unowned)), 12 SECONDS)
@@ -146,12 +146,14 @@
 	else
 		return ..()
 
-/obj/item/organ/internal/heart/cursed/on_insert(mob/living/carbon/accursed)
+/obj/item/organ/internal/heart/cursed/on_mob_insert(mob/living/carbon/accursed)
 	. = ..()
+
 	accursed.AddComponent(/datum/component/manual_heart, pump_delay = pump_delay, blood_loss = blood_loss, heal_brute = heal_brute, heal_burn = heal_burn, heal_oxy = heal_oxy)
 
-/obj/item/organ/internal/heart/cursed/Remove(mob/living/carbon/accursed, special = FALSE)
+/obj/item/organ/internal/heart/cursed/on_mob_remove(mob/living/carbon/accursed, special = FALSE)
 	. = ..()
+
 	qdel(accursed.GetComponent(/datum/component/manual_heart))
 
 /obj/item/organ/internal/heart/cybernetic

code/modules/surgery/organs/internal/heart/heart_ethereal.dm

@@ -21,7 +21,7 @@
 	add_atom_colour(ethereal_color, FIXED_COLOUR_PRIORITY)
 	update_appearance()
 
-/obj/item/organ/internal/heart/ethereal/Insert(mob/living/carbon/heart_owner, special = FALSE, drop_if_replaced = TRUE)
+/obj/item/organ/internal/heart/ethereal/Insert(mob/living/carbon/heart_owner, special = FALSE, movement_flags)
 	. = ..()
 	if(!.)
 		return
@@ -29,7 +29,7 @@
 	RegisterSignal(heart_owner, COMSIG_LIVING_POST_FULLY_HEAL, PROC_REF(on_owner_fully_heal))
 	RegisterSignal(heart_owner, COMSIG_QDELETING, PROC_REF(owner_deleted))
 
-/obj/item/organ/internal/heart/ethereal/Remove(mob/living/carbon/heart_owner, special = FALSE)
+/obj/item/organ/internal/heart/ethereal/Remove(mob/living/carbon/heart_owner, special, movement_flags)
 	UnregisterSignal(heart_owner, list(COMSIG_MOB_STATCHANGE, COMSIG_LIVING_POST_FULLY_HEAL, COMSIG_QDELETING))
 	REMOVE_TRAIT(heart_owner, TRAIT_CORPSELOCKED, SPECIES_TRAIT)
 	stop_crystalization_process(heart_owner)

code/modules/surgery/organs/internal/liver/_liver.dm

@@ -61,12 +61,12 @@
 	qdel(GetComponent(/datum/component/squeak))
 
 /// Registers COMSIG_SPECIES_HANDLE_CHEMICAL from owner
-/obj/item/organ/internal/liver/on_insert(mob/living/carbon/organ_owner, special)
+/obj/item/organ/internal/liver/on_mob_insert(mob/living/carbon/organ_owner, special)
 	. = ..()
 	RegisterSignal(organ_owner, COMSIG_SPECIES_HANDLE_CHEMICAL, PROC_REF(handle_chemical))
 
 /// Unregisters COMSIG_SPECIES_HANDLE_CHEMICAL from owner
-/obj/item/organ/internal/liver/on_remove(mob/living/carbon/organ_owner, special)
+/obj/item/organ/internal/liver/on_mob_remove(mob/living/carbon/organ_owner, special)
 	. = ..()
 	UnregisterSignal(organ_owner, COMSIG_SPECIES_HANDLE_CHEMICAL)
 
@@ -134,7 +134,7 @@
 		return
 
 	var/obj/belly = owner.get_organ_slot(ORGAN_SLOT_STOMACH)
-	var/list/cached_reagents = owner.reagents.reagent_list
+	var/list/cached_reagents = owner.reagents?.reagent_list
 	var/liver_damage = 0
 	var/provide_pain_message = HAS_NO_TOXIN
 
@@ -152,7 +152,7 @@
 			if(provide_pain_message != HAS_PAINFUL_TOXIN)
 				provide_pain_message = toxin.silent_toxin ? HAS_SILENT_TOXIN : HAS_PAINFUL_TOXIN
 
-	owner.reagents.metabolize(owner, seconds_per_tick, times_fired, can_overdose = TRUE)
+	owner.reagents?.metabolize(owner, seconds_per_tick, times_fired, can_overdose = TRUE)
 
 	if(liver_damage)
 		apply_organ_damage(min(liver_damage * seconds_per_tick , MAX_TOXIN_LIVER_DAMAGE * seconds_per_tick))

code/modules/surgery/organs/internal/lungs/_lungs.dm

@@ -153,7 +153,7 @@
 	add_gas_reaction(/datum/gas/zauker, while_present = PROC_REF(too_much_zauker))
 
 ///Simply exists so that you don't keep any alerts from your previous lack of lungs.
-/obj/item/organ/internal/lungs/Insert(mob/living/carbon/receiver, special = FALSE, drop_if_replaced = TRUE)
+/obj/item/organ/internal/lungs/Insert(mob/living/carbon/receiver, special = FALSE, movement_flags)
 	. = ..()
 	if(!.)
 		return .
@@ -163,7 +163,7 @@
 	receiver.clear_alert(ALERT_NOT_ENOUGH_PLASMA)
 	receiver.clear_alert(ALERT_NOT_ENOUGH_N2O)
 
-/obj/item/organ/internal/lungs/Remove(mob/living/carbon/organ_owner, special)
+/obj/item/organ/internal/lungs/Remove(mob/living/carbon/organ_owner, special, movement_flags)
 	. = ..()
 	// This is very "manual" I realize, but it's useful to ensure cleanup for gases we're removing happens
 	// Avoids stuck alerts and such

code/modules/surgery/organs/internal/stomach/_stomach.dm

@@ -55,7 +55,7 @@
 	var/mob/living/carbon/body = owner
 
 	// digest food, sent all reagents that can metabolize to the body
-	for(var/datum/reagent/bit as anything in reagents.reagent_list)
+	for(var/datum/reagent/bit as anything in reagents?.reagent_list)
 
 		// If the reagent does not metabolize then it will sit in the stomach
 		// This has an effect on items like plastic causing them to take up space in the stomach
@@ -93,7 +93,7 @@
 		return
 
 	//We are checking if we have nutriment in a damaged stomach.
-	var/datum/reagent/nutri = locate(/datum/reagent/consumable/nutriment) in reagents.reagent_list
+	var/datum/reagent/nutri = locate(/datum/reagent/consumable/nutriment) in reagents?.reagent_list
 	//No nutriment found lets exit out
 	if(!nutri)
 		return
@@ -262,7 +262,7 @@
 			disgusted.throw_alert(ALERT_DISGUST, /atom/movable/screen/alert/disgusted)
 			disgusted.add_mood_event("disgust", /datum/mood_event/disgusted)
 
-/obj/item/organ/internal/stomach/Remove(mob/living/carbon/stomach_owner, special = 0)
+/obj/item/organ/internal/stomach/Remove(mob/living/carbon/stomach_owner, special, movement_flags)
 	if(ishuman(stomach_owner))
 		var/mob/living/carbon/human/human_owner = owner
 		human_owner.clear_alert(ALERT_DISGUST)

code/modules/surgery/organs/internal/stomach/stomach_ethereal.dm

@@ -13,12 +13,12 @@
 	adjust_charge(-ETHEREAL_CHARGE_FACTOR * seconds_per_tick)
 	handle_charge(owner, seconds_per_tick, times_fired)
 
-/obj/item/organ/internal/stomach/ethereal/on_insert(mob/living/carbon/stomach_owner)
+/obj/item/organ/internal/stomach/ethereal/on_mob_insert(mob/living/carbon/stomach_owner)
 	. = ..()
 	RegisterSignal(stomach_owner, COMSIG_PROCESS_BORGCHARGER_OCCUPANT, PROC_REF(charge))
 	RegisterSignal(stomach_owner, COMSIG_LIVING_ELECTROCUTE_ACT, PROC_REF(on_electrocute))
 
-/obj/item/organ/internal/stomach/ethereal/on_remove(mob/living/carbon/stomach_owner)
+/obj/item/organ/internal/stomach/ethereal/on_mob_remove(mob/living/carbon/stomach_owner)
 	. = ..()
 	UnregisterSignal(stomach_owner, COMSIG_PROCESS_BORGCHARGER_OCCUPANT)
 	UnregisterSignal(stomach_owner, COMSIG_LIVING_ELECTROCUTE_ACT)

code/modules/surgery/organs/internal/stomach/stomach_golem.dm

@@ -11,11 +11,11 @@
 	/// How slow are you if you have absolutely nothing in the tank?
 	var/max_hunger_slowdown = 4
 
-/obj/item/organ/internal/stomach/golem/on_insert(mob/living/carbon/organ_owner, special)
+/obj/item/organ/internal/stomach/golem/on_mob_insert(mob/living/carbon/organ_owner, special)
 	. = ..()
 	RegisterSignal(owner, COMSIG_CARBON_ATTEMPT_EAT, PROC_REF(try_eating))
 
-/obj/item/organ/internal/stomach/golem/on_remove(mob/living/carbon/organ_owner, special)
+/obj/item/organ/internal/stomach/golem/on_mob_remove(mob/living/carbon/organ_owner, special)
 	. = ..()
 	UnregisterSignal(organ_owner, COMSIG_CARBON_ATTEMPT_EAT)
 	organ_owner.remove_movespeed_modifier(/datum/movespeed_modifier/golem_hunger)

code/modules/surgery/organs/internal/tongue/_tongue.dm

@@ -120,7 +120,7 @@
 		food_taste_reaction = FOOD_LIKED
 	return food_taste_reaction
 
-/obj/item/organ/internal/tongue/Insert(mob/living/carbon/tongue_owner, special = FALSE, drop_if_replaced = TRUE)
+/obj/item/organ/internal/tongue/Insert(mob/living/carbon/tongue_owner, special = FALSE, movement_flags)
 	. = ..()
 	if(!.)
 		return
@@ -135,7 +135,7 @@
 	REMOVE_TRAIT(tongue_owner, TRAIT_AGEUSIA, NO_TONGUE_TRAIT)
 	apply_tongue_effects()
 
-/obj/item/organ/internal/tongue/Remove(mob/living/carbon/tongue_owner, special = FALSE)
+/obj/item/organ/internal/tongue/Remove(mob/living/carbon/tongue_owner, special, movement_flags)
 	. = ..()
 	temp_say_mod = ""
 	UnregisterSignal(tongue_owner, COMSIG_MOB_SAY)

code/modules/surgery/organs/organ_movement.dm

@@ -0,0 +1,230 @@
+// There are two kinds of organ movement: mob movement and limb movement
+// If you pull someones brain out, you remove it from the mob and the limb
+// If you take someones head off, you remove it from the mob but not the limb
+// If you remove the brain from an already decapitated head, you remove it from the limb but not the mob
+
+// Keep the seperation of limb removal and mob removal absolute
+
+/*
+ * Insert the organ into the select mob.
+ *
+ * receiver - the mob who will get our organ
+ * special - "quick swapping" an organ out - when TRUE, the mob will be unaffected by not having that organ for the moment
+ * movement_flags - Flags for how we behave in movement. See DEFINES/organ_movement for flags
+ */
+/obj/item/organ/proc/Insert(mob/living/carbon/receiver, special = FALSE, movement_flags)
+	SHOULD_CALL_PARENT(TRUE)
+
+	mob_insert(receiver, special, movement_flags)
+	bodypart_insert(limb_owner = receiver, movement_flags = movement_flags)
+
+	return TRUE
+
+/*
+ * Remove the organ from the select mob.
+ *
+ * * organ_owner - the mob who owns our organ, that we're removing the organ from. Can be null
+ * * special - "quick swapping" an organ out - when TRUE, the mob will be unaffected by not having that organ for the moment
+ */
+/obj/item/organ/proc/Remove(mob/living/carbon/organ_owner, special = FALSE, movement_flags)
+	SHOULD_CALL_PARENT(TRUE)
+
+	mob_remove(organ_owner, special, movement_flags)
+	bodypart_remove(null, organ_owner, movement_flags)
+
+/*
+ * Insert the organ into the select mob.
+ *
+ * receiver - the mob who will get our organ
+ * special - "quick swapping" an organ out - when TRUE, the mob will be unaffected by not having that organ for the moment
+ * movement_flags - Flags for how we behave in movement. See DEFINES/organ_movement for flags
+ */
+/obj/item/organ/proc/mob_insert(mob/living/carbon/receiver, special, movement_flags)
+	SHOULD_CALL_PARENT(TRUE)
+
+	if(!iscarbon(receiver))
+		stack_trace("Tried to insert organ into non-carbon: [receiver.type]")
+		return
+
+	if(owner == receiver)
+		stack_trace("Organ receiver is already organ owner")
+		return
+
+	var/obj/item/organ/replaced = receiver.get_organ_slot(slot)
+	if(replaced)
+		replaced.Remove(receiver, special = TRUE)
+		if(movement_flags & DELETE_IF_REPLACED)
+			qdel(replaced)
+		else
+			replaced.forceMove(get_turf(receiver))
+
+		if(!IS_ROBOTIC_ORGAN(src) && (organ_flags & ORGAN_VIRGIN))
+			blood_dna_info = receiver.get_blood_dna_list()
+			// need to remove the synethic blood DNA that is initialized
+			// wash also adds the blood dna again
+			wash(CLEAN_TYPE_BLOOD)
+			organ_flags &= ~ORGAN_VIRGIN
+
+	receiver.organs |= src
+	receiver.organs_slot[slot] = src
+	owner = receiver
+
+	on_mob_insert(receiver, special)
+
+	return TRUE
+
+/// Called after the organ is inserted into a mob.
+/// Adds Traits, Actions, and Status Effects on the mob in which the organ is impanted.
+/// Override this proc to create unique side-effects for inserting your organ. Must be called by overrides.
+/obj/item/organ/proc/on_mob_insert(mob/living/carbon/organ_owner, special = FALSE, movement_flags)
+	SHOULD_CALL_PARENT(TRUE)
+
+	for(var/trait in organ_traits)
+		ADD_TRAIT(organ_owner, trait, REF(src))
+
+	for(var/datum/action/action as anything in actions)
+		action.Grant(organ_owner)
+
+	for(var/datum/status_effect/effect as anything in organ_effects)
+		organ_owner.apply_status_effect(effect, type)
+
+	RegisterSignal(owner, COMSIG_ATOM_EXAMINE, PROC_REF(on_owner_examine))
+	SEND_SIGNAL(src, COMSIG_ORGAN_IMPLANTED, organ_owner)
+	SEND_SIGNAL(organ_owner, COMSIG_CARBON_GAIN_ORGAN, src, special)
+
+/// Insert an organ into a limb, assume the limb as always detached and include no owner operations here (except the get_bodypart helper here I guess)
+/// Give EITHER a limb OR a limb owner
+/obj/item/organ/proc/bodypart_insert(obj/item/bodypart/bodypart, mob/living/carbon/limb_owner, movement_flags)
+	SHOULD_CALL_PARENT(TRUE)
+
+	if(limb_owner)
+		bodypart = limb_owner.get_bodypart(deprecise_zone(zone))
+
+	// The true movement
+	forceMove(bodypart)
+	bodypart.contents |= src
+	bodypart_owner = bodypart
+
+	RegisterSignal(src, COMSIG_MOVABLE_MOVED, PROC_REF(forced_removal))
+
+	// Apply unique side-effects. Return value does not matter.
+	on_bodypart_insert(bodypart)
+
+	return TRUE
+
+/// Add any limb specific effects you might want here
+/obj/item/organ/proc/on_bodypart_insert(obj/item/bodypart/limb, movement_flags)
+	SHOULD_CALL_PARENT(TRUE)
+
+	item_flags |= ABSTRACT
+	ADD_TRAIT(src, TRAIT_NODROP, ORGAN_INSIDE_BODY_TRAIT)
+
+/*
+ * Remove the organ from the select mob.
+ *
+ * * organ_owner - the mob who owns our organ, that we're removing the organ from. Can be null
+ * * special - "quick swapping" an organ out - when TRUE, the mob will be unaffected by not having that organ for the moment
+ */
+/obj/item/organ/proc/mob_remove(mob/living/carbon/organ_owner, special = FALSE, movement_flags)
+	SHOULD_CALL_PARENT(TRUE)
+
+	if(organ_owner)
+		if(organ_owner.organs_slot[slot] == src)
+			organ_owner.organs_slot.Remove(slot)
+		organ_owner.organs -= src
+
+	owner = null
+
+	on_mob_remove(organ_owner, special)
+
+	return TRUE
+
+/// Called after the organ is removed from a mob.
+/// Removes Traits, Actions, and Status Effects on the mob in which the organ was impanted.
+/// Override this proc to create unique side-effects for removing your organ. Must be called by overrides.
+/obj/item/organ/proc/on_mob_remove(mob/living/carbon/organ_owner, special = FALSE, movement_flags)
+	SHOULD_CALL_PARENT(TRUE)
+
+	if(!iscarbon(organ_owner))
+		stack_trace("Organ removal should not be happening on non carbon mobs: [organ_owner]")
+
+	for(var/trait in organ_traits)
+		REMOVE_TRAIT(organ_owner, trait, REF(src))
+
+	for(var/datum/action/action as anything in actions)
+		action.Remove(organ_owner)
+
+	for(var/datum/status_effect/effect as anything in organ_effects)
+		organ_owner.remove_status_effect(effect, type)
+
+	UnregisterSignal(organ_owner, COMSIG_ATOM_EXAMINE)
+	SEND_SIGNAL(src, COMSIG_ORGAN_REMOVED, organ_owner)
+	SEND_SIGNAL(organ_owner, COMSIG_CARBON_LOSE_ORGAN, src, special)
+
+	var/list/diseases = organ_owner.get_static_viruses()
+	if(!LAZYLEN(diseases))
+		return
+
+	var/list/datum/disease/diseases_to_add = list()
+	for(var/datum/disease/disease as anything in diseases)
+		// robotic organs are immune to disease unless 'inorganic biology' symptom is present
+		if(IS_ROBOTIC_ORGAN(src) && !(disease.infectable_biotypes & MOB_ROBOTIC))
+			continue
+
+		// admin or special viruses that should not be reproduced
+		if(disease.spread_flags & (DISEASE_SPREAD_SPECIAL | DISEASE_SPREAD_NON_CONTAGIOUS))
+			continue
+
+		diseases_to_add += disease
+
+	if(LAZYLEN(diseases_to_add))
+		AddComponent(/datum/component/infective, diseases_to_add)
+
+/// Called to remove an organ from a limb. Do not put any mob operations here (except the bodypart_getter at the start)
+/// Give EITHER a limb OR a limb_owner
+/obj/item/organ/proc/bodypart_remove(obj/item/bodypart/limb, mob/living/carbon/limb_owner, movement_flags)
+	SHOULD_CALL_PARENT(TRUE)
+
+	if(limb_owner)
+		limb = limb_owner.get_bodypart(deprecise_zone(zone))
+
+	UnregisterSignal(src, COMSIG_MOVABLE_MOVED) //DONT MOVE THIS!!!! we moves the organ right after, so we unregister before we move them physically
+
+	// The true movement is here
+	moveToNullspace()
+	bodypart_owner.contents -= src
+	bodypart_owner = null
+
+	on_bodypart_remove(limb)
+
+	return TRUE
+
+/// Called on limb removal to remove limb specific limb effects or statusses
+/obj/item/organ/proc/on_bodypart_remove(obj/item/bodypart/limb, movement_flags)
+	SHOULD_CALL_PARENT(TRUE)
+
+	if(!IS_ROBOTIC_ORGAN(src) && !(item_flags & NO_BLOOD_ON_ITEM) && !QDELING(src))
+		AddElement(/datum/element/decal/blood)
+
+	item_flags &= ~ABSTRACT
+	REMOVE_TRAIT(src, TRAIT_NODROP, ORGAN_INSIDE_BODY_TRAIT)
+
+/// In space station videogame, nothing is sacred. If somehow an organ is removed unexpectedly, handle it properly
+/obj/item/organ/proc/forced_removal()
+	SIGNAL_HANDLER
+
+	if(owner)
+		Remove(owner)
+	else if(bodypart_owner)
+		bodypart_remove(limb_owner = owner)
+	else
+		stack_trace("Force removed an already removed organ!")
+
+/**
+ * Proc that gets called when the organ is surgically removed by someone, can be used for special effects
+ * Currently only used so surplus organs can explode when surgically removed.
+ */
+/obj/item/organ/proc/on_surgical_removal(mob/living/user, mob/living/carbon/old_owner, target_zone, obj/item/tool)
+	SHOULD_CALL_PARENT(TRUE)
+	SEND_SIGNAL(src, COMSIG_ORGAN_SURGICALLY_REMOVED, user, old_owner, target_zone, tool)
+	RemoveElement(/datum/element/decal/blood)

code/modules/unit_tests/_unit_tests.dm

@@ -195,6 +195,7 @@
 #include "objectives.dm"
 #include "operating_table.dm"
 #include "orderable_items.dm"
+#include "organ_bodypart_shuffle.dm"
 #include "organ_set_bonus.dm"
 #include "organs.dm"
 #include "outfit_sanity.dm"

code/modules/unit_tests/heretic_rituals.dm

@@ -66,7 +66,10 @@
 			if(islist(ritual_item_path))
 				ritual_item_path = pick(ritual_item_path)
 			for(var/i in 1 to amount_to_create)
-				created_atoms += new ritual_item_path(get_turf(our_heretic))
+				var/obj/item/item = new ritual_item_path(get_turf(our_heretic))
+				if(isitem(item))
+					item.item_flags &= ~ABSTRACT
+				created_atoms += item
 
 		// Now, we can ACTUALLY run the ritual. Let's do it.
 		// Attempt to run the knowledge via the sacrifice rune.
@@ -106,6 +109,10 @@
 		for(var/atom/thing as anything in nearby_atoms)
 			if(!ismovable(thing))
 				continue
+			if(isitem(thing))
+				var/obj/item/item = thing
+				if(item.item_flags & ABSTRACT) //bodyparts and stuff will get registered otherwise
+					continue
 
 			// There are atoms around the rune still, and there shouldn't be.
 			// All component atoms were consumed, and all resulting atoms were cleaned up.

code/modules/unit_tests/human_through_recycler.dm

@@ -17,8 +17,13 @@
 	TEST_ASSERT_EQUAL(damage_incurred, chewer.crush_damage, "Assistant did not take the expected amount of brute damage ([chewer.crush_damage]) from the emagged recycler! Took ([damage_incurred]) instead.")
 	TEST_ASSERT(chewer.bloody, "The emagged recycler did not become bloody after crushing the assistant!")
 
+	var/list/bad_contents = assistant.contents
+	for(var/obj/item/item in assistant.contents)
+		if(item.item_flags & ABSTRACT)
+			bad_contents -= item
+
 	// Now, let's test to see if all of their clothing got properly deleted.
-	TEST_ASSERT_EQUAL(length(assistant.contents), 0, "Assistant still has items in its contents after being put through an emagged recycler!")
+	TEST_ASSERT_EQUAL(length(bad_contents), 0, "Assistant still has items in its contents after being put through an emagged recycler!")
 	// Consistent Assistants will always have the following: ID, PDA, backpack, a uniform, a headset, and a pair of shoes. If any of these are still present, then the recycler did not properly delete the assistant's clothing.
 	// However, let's check for EVERYTHING just in case, because we don't want to miss anything.
 	// This is just what we expect to be deleted.

code/modules/unit_tests/ling_decap.dm

@@ -9,7 +9,7 @@
 	var/obj/item/bodypart/head/noggin = ling.get_bodypart(BODY_ZONE_HEAD)
 	noggin.dismember()
 	TEST_ASSERT_NULL(ling.get_bodypart(BODY_ZONE_HEAD), "Changeling failed to be decapitated.")
-	TEST_ASSERT_NULL(noggin.brainmob.mind, "Changeling's mind was moved to their head after decapitation, but it should have remained in their body.")
+	TEST_ASSERT_NULL(noggin.brain.brainmob.mind, "Changeling's mind was moved to their brain after decapitation, but it should have remained in their body.")
 
 	var/obj/item/organ/internal/brain/oldbrain = noggin.brain
 	noggin.drop_organs()
@@ -33,7 +33,7 @@
 
 	var/obj/item/bodypart/head/noggin = normal_guy.get_bodypart(BODY_ZONE_HEAD)
 	noggin.dismember()
-	TEST_ASSERT_EQUAL(noggin.brainmob.mind, my_guys_mind, "Dummy's mind was not moved to their head after decapitation.")
+	TEST_ASSERT_EQUAL(noggin.brain.brainmob.mind, my_guys_mind, "Dummy's mind was not moved to their brain after decapitation.")
 
 	var/obj/item/organ/internal/brain/oldbrain = noggin.brain
 	noggin.drop_organs()

code/modules/unit_tests/organ_bodypart_shuffle.dm

@@ -0,0 +1,34 @@
+/// Moves organs in and out of bodyparts, and moves the bodyparts around to see if someone didn't fuck up their movement
+/datum/unit_test/organ_bodypart_shuffle
+
+/datum/unit_test/organ_bodypart_shuffle/Run()
+	var/mob/living/carbon/human/hollow_boy = allocate(/mob/living/carbon/human/consistent)
+
+	// Test if organs are all properly updating when forcefully removed
+	var/list/removed_organs = list()
+
+	for(var/obj/item/organ/organ as anything in hollow_boy.organs)
+		organ.moveToNullspace()
+		removed_organs += organ
+
+	for(var/obj/item/organ/organ as anything in removed_organs)
+		TEST_ASSERT(!(organ in hollow_boy.organs), "Organ '[organ.name] remained inside human after forceMove into nullspace.")
+		TEST_ASSERT(organ.loc == null, "Organ '[organ.name] did not move to nullspace after being forced to.")
+		TEST_ASSERT(!(organ.owner), "Organ '[organ.name] kept reference to human after forceMove into nullspace.")
+		TEST_ASSERT(!(organ.bodypart_owner), "Organ '[organ.name] kept reference to bodypart after forceMove into nullspace.")
+
+	for(var/obj/item/bodypart/bodypart as anything in hollow_boy.bodyparts)
+		bodypart = new bodypart.type() //fresh, duplice bodypart with no insides
+		for(var/obj/item/organ/organ as anything in removed_organs)
+			if(bodypart.body_zone != deprecise_zone(organ.zone))
+				continue
+			organ.bodypart_insert(bodypart) // Put all the old organs back in
+		bodypart.replace_limb(hollow_boy) //so stick new bodyparts on them with their old organs
+		// Check if, after we put the old organs in a new limb, and after we put that new limb on the mob, if the organs came with
+		for(var/obj/item/organ/organ as anything in removed_organs) //technically readded organ now
+			if(bodypart.body_zone != deprecise_zone(organ.zone))
+				continue
+			TEST_ASSERT(organ in hollow_boy.organs, "Organ '[organ.name] was put in an empty bodypart that replaced a humans, but the organ did not come with.")
+
+	// Test if bodyparts are all properly updating when forcefully removed
+	hollow_boy = allocate(/mob/living/carbon/human/consistent) //freshly filled with wet insides

code/modules/unit_tests/organ_set_bonus.dm

@@ -30,7 +30,7 @@
 		// Attempt to insert entire list of mutant organs for the given infusion_entry.
 		for(var/obj/item/organ/organ as anything in output_organs)
 			organ = new organ()
-			TEST_ASSERT(organ.Insert(lab_rat, special = TRUE, drop_if_replaced = FALSE), "The organ `[organ.type]` for `[infuser_entry.type]` was not inserted in the mob when expected, Insert() returned falsy when TRUE was expected.")
+			TEST_ASSERT(organ.Insert(lab_rat, special = TRUE, movement_flags = DELETE_IF_REPLACED), "The organ `[organ.type]` for `[infuser_entry.type]` was not inserted in the mob when expected, Insert() returned falsy when TRUE was expected.")
 			inserted_organs += organ
 
 		// Search for added Status Effect.

code/modules/unit_tests/organs.dm

@@ -25,14 +25,10 @@
 	))
 
 /datum/unit_test/organ_sanity/Run()
-	for(var/obj/item/organ/organ_type as anything in subtypesof(/obj/item/organ))
+	for(var/obj/item/organ/organ_type as anything in subtypesof(/obj/item/organ) - test_organ_blacklist)
 		organ_test_insert(organ_type)
 
 /datum/unit_test/organ_sanity/proc/organ_test_insert(obj/item/organ/organ_type)
-	// Skip prototypes.
-	if(test_organ_blacklist[organ_type])
-		return
-
 	// Appropriate mob (Human) which will receive organ.
 	var/mob/living/carbon/human/lab_rat = allocate(/mob/living/carbon/human/consistent)
 	var/obj/item/organ/test_organ = new organ_type()
@@ -41,8 +37,8 @@
 	var/mob/living/basic/pet/dog/lab_dog = allocate(/mob/living/basic/pet/dog/corgi)
 	var/obj/item/organ/reject_organ = new organ_type()
 
-	TEST_ASSERT(test_organ.Insert(lab_rat, special = TRUE, drop_if_replaced = FALSE), TEST_ORGAN_INSERT_MESSAGE(test_organ, "should return TRUE to indicate success."))
-	TEST_ASSERT(!reject_organ.Insert(lab_dog, special = TRUE, drop_if_replaced = FALSE), TEST_ORGAN_INSERT_MESSAGE(test_organ, "shouldn't return TRUE when inserting into a basic mob (Corgi)."))
+	TEST_ASSERT(test_organ.Insert(lab_rat, special = TRUE, movement_flags = DELETE_IF_REPLACED), TEST_ORGAN_INSERT_MESSAGE(test_organ, "should return TRUE to indicate success."))
+	TEST_ASSERT(!reject_organ.Insert(lab_dog, special = TRUE, movement_flags = DELETE_IF_REPLACED), TEST_ORGAN_INSERT_MESSAGE(test_organ, "shouldn't return TRUE when inserting into a basic mob (Corgi)."))
 
 	// Species change swaps out all the organs, making test_organ un-usable by this point.
 	if(species_changing_organs[test_organ.type])

code/modules/unit_tests/species_change_organs.dm

@@ -12,7 +12,7 @@
 	dummy.gain_trauma(/datum/brain_trauma/severe/blindness)
 	// Give a cyber heart
 	var/obj/item/organ/internal/heart/cybernetic/cyber_heart = allocate(/obj/item/organ/internal/heart/cybernetic)
-	cyber_heart.Insert(dummy, special = TRUE, drop_if_replaced = FALSE)
+	cyber_heart.Insert(dummy, special = TRUE, movement_flags = DELETE_IF_REPLACED)
 	// Give one of their organs a bit of damage
 	var/obj/item/organ/internal/appendix/existing_appendix = dummy.get_organ_slot(ORGAN_SLOT_APPENDIX)
 	existing_appendix.set_organ_damage(25)

code/modules/unit_tests/tail_wag.dm

@@ -6,7 +6,7 @@
 /datum/unit_test/tail_wag/Run()
 	var/mob/living/carbon/human/dummy = allocate(/mob/living/carbon/human/consistent)
 	var/obj/item/organ/external/tail/cat/dummy_tail = allocate(/obj/item/organ/external/tail/cat)
-	dummy_tail.Insert(dummy, special = TRUE, drop_if_replaced = FALSE)
+	dummy_tail.Insert(dummy, special = TRUE, movement_flags = DELETE_IF_REPLACED)
 
 	// SANITY TEST
 
@@ -74,7 +74,7 @@
 	// TESTING MOB DEATH
 
 	// put it back and start wagging again
-	dummy_tail.Insert(dummy, special = TRUE, drop_if_replaced = FALSE)
+	dummy_tail.Insert(dummy, special = TRUE, movement_flags = DELETE_IF_REPLACED)
 	SEND_SIGNAL(dummy, COMSIG_ORGAN_WAG_TAIL, TRUE)
 	if(!(dummy_tail.wag_flags & WAG_WAGGING))
 		TEST_FAIL("Tail did not start wagging when it should have!")

code/modules/wiremod/shell/brain_computer_interface.dm

@@ -17,11 +17,6 @@
 		new /obj/item/circuit_component/bci_core,
 	), SHELL_CAPACITY_SMALL, starting_circuit = circuit)
 
-/obj/item/organ/internal/cyberimp/bci/on_insert(mob/living/carbon/receiver)
-	. = ..()
-	// Organs are put in nullspace, but this breaks circuit interactions
-	forceMove(receiver)
-
 /obj/item/organ/internal/cyberimp/bci/say(message, bubble_type, list/spans, sanitize, datum/language/language, ignore_spam, forced = null, filterproof = null, message_range = 7, datum/saymode/saymode = null)
 	if (owner)
 		// Otherwise say_dead will be called.

code/modules/zombie/organs.dm

@@ -23,25 +23,25 @@
 	GLOB.zombie_infection_list -= src
 	. = ..()
 
-/obj/item/organ/internal/zombie_infection/Insert(mob/living/carbon/M, special = FALSE, drop_if_replaced = TRUE)
+/obj/item/organ/internal/zombie_infection/on_mob_insert(mob/living/carbon/M, special = FALSE, movement_flags)
 	. = ..()
 	if(!.)
 		return .
 	START_PROCESSING(SSobj, src)
 
-/obj/item/organ/internal/zombie_infection/Remove(mob/living/carbon/M, special = FALSE)
+/obj/item/organ/internal/zombie_infection/on_mob_remove(mob/living/carbon/M, special = FALSE)
 	. = ..()
 	STOP_PROCESSING(SSobj, src)
-	if(iszombie(M) && old_species && !special && !QDELETED(src))
+	if(iszombie(M) && old_species && !special)
 		M.set_species(old_species)
 	if(timer_id)
 		deltimer(timer_id)
 
-/obj/item/organ/internal/zombie_infection/on_insert(mob/living/carbon/organ_owner, special)
+/obj/item/organ/internal/zombie_infection/on_mob_insert(mob/living/carbon/organ_owner, special)
 	. = ..()
 	RegisterSignal(organ_owner, COMSIG_LIVING_DEATH, PROC_REF(organ_owner_died))
 
-/obj/item/organ/internal/zombie_infection/on_remove(mob/living/carbon/organ_owner, special)
+/obj/item/organ/internal/zombie_infection/on_mob_remove(mob/living/carbon/organ_owner, special)
 	. = ..()
 	UnregisterSignal(organ_owner, COMSIG_LIVING_DEATH)
 

tgstation.dme

@@ -159,6 +159,7 @@
 #include "code\__DEFINES\nuclear_bomb.dm"
 #include "code\__DEFINES\obj_flags.dm"
 #include "code\__DEFINES\observers.dm"
+#include "code\__DEFINES\organ_movement.dm"
 #include "code\__DEFINES\overlays.dm"
 #include "code\__DEFINES\pai.dm"
 #include "code\__DEFINES\paintings.dm"
@@ -5670,6 +5671,7 @@
 #include "code\modules\surgery\organs\_organ.dm"
 #include "code\modules\surgery\organs\autosurgeon.dm"
 #include "code\modules\surgery\organs\helpers.dm"
+#include "code\modules\surgery\organs\organ_movement.dm"
 #include "code\modules\surgery\organs\external\_external_organ.dm"
 #include "code\modules\surgery\organs\external\restyling.dm"
 #include "code\modules\surgery\organs\external\spines.dm"