diff --git a/code/modules/mob/living/brain/brain_item.dm b/code/modules/mob/living/brain/brain_item.dm
index 13a34b6bae..fd7b8a8db3 100644
--- a/code/modules/mob/living/brain/brain_item.dm
+++ b/code/modules/mob/living/brain/brain_item.dm
@@ -18,12 +18,12 @@
 	vital = FALSE
 	decoy_override = TRUE
 
-/obj/item/organ/brain/Insert(mob/living/carbon/C, special = 0)
+/obj/item/organ/brain/Insert(mob/living/carbon/C, special = 0,no_id_transfer = FALSE)
 	..()
 
 	name = "brain"
 
-	if(C.mind && C.mind.changeling)	//congrats, you're trapped in a body you don't control
+	if(C.mind && C.mind.changeling && !no_id_transfer)	//congrats, you're trapped in a body you don't control
 		if(brainmob && !(C.stat == DEAD || (C.status_flags & FAKEDEATH)))
 			to_chat(brainmob, "<span class = danger>You can't feel your body! You're still just a brain!</span>")
 		loc = C
@@ -44,13 +44,9 @@
 	//Update the body's icon so it doesnt appear debrained anymore
 	C.update_hair()
 
-/obj/item/organ/brain/Remove(mob/living/carbon/C, special = 0)
+/obj/item/organ/brain/Remove(mob/living/carbon/C, special = 0,no_id_transfer = FALSE)
 	..()
-	if(!special)
-		if(C.has_brain_worms())
-			var/mob/living/simple_animal/borer/B = C.has_brain_worms()
-			B.leave_victim() //Should remove borer if the brain is removed - RR
-	if(!gc_destroyed || (owner && !owner.gc_destroyed))
+	if((!gc_destroyed || (owner && !owner.gc_destroyed)) && !no_id_transfer)
 		transfer_identity(C)
 	C.update_hair()
 
diff --git a/code/modules/mob/living/carbon/human/human.dm b/code/modules/mob/living/carbon/human/human.dm
index d66e6f808a..70a5f5225c 100644
--- a/code/modules/mob/living/carbon/human/human.dm
+++ b/code/modules/mob/living/carbon/human/human.dm
@@ -21,41 +21,12 @@
 		set_species(dna.species.type)
 
 	//initialise organs
-	create_internal_organs()
+	create_internal_organs() //most of it is done in set_species now, this is only for parent call
 
 	handcrafting = new()
 
 	. = ..()
 
-/mob/living/carbon/human/create_internal_organs()
-	if(!(NOHUNGER in dna.species.species_traits))
-		internal_organs += new /obj/item/organ/appendix
-	if(!(NOBREATH in dna.species.species_traits))
-		if(dna.species.mutantlungs)
-			internal_organs += new dna.species.mutantlungs()
-		else
-			internal_organs += new /obj/item/organ/lungs()
-	if(!(NOBLOOD in dna.species.species_traits))
-		internal_organs += new /obj/item/organ/heart
-
-	if(!(NOLIVER in dna.species.species_traits))
-		if(dna.species.mutantliver)
-			internal_organs += new dna.species.mutantliver()
-		else
-			internal_organs += new /obj/item/organ/liver()
-
-	if(!(NOSTOMACH in dna.species.species_traits))
-		if(dna.species.mutantstomach)
-			internal_organs += new dna.species.mutantstomach()
-		else
-			internal_organs += new /obj/item/organ/stomach()
-
-	internal_organs += new dna.species.mutanteyes
-	internal_organs += new dna.species.mutantears
-	internal_organs += new dna.species.mutanttongue
-	internal_organs += new /obj/item/organ/brain
-	..()
-
 /mob/living/carbon/human/OpenCraftingMenu()
 	handcrafting.ui_interact(src)
 
diff --git a/code/modules/mob/living/carbon/human/species.dm b/code/modules/mob/living/carbon/human/species.dm
index 07f3acea48..34d4ae8e51 100644
--- a/code/modules/mob/living/carbon/human/species.dm
+++ b/code/modules/mob/living/carbon/human/species.dm
@@ -68,7 +68,8 @@
 
 	//Flight and floating
 	var/override_float = 0
-
+	
+	var/obj/item/organ/brain/mutant_brain = /obj/item/organ/brain
 	var/obj/item/organ/eyes/mutanteyes = /obj/item/organ/eyes
 	var/obj/item/organ/ears/mutantears = /obj/item/organ/ears
 	var/obj/item/mutanthands
@@ -123,6 +124,113 @@
 		return 0
 	return 1
 
+//Will regenerate missing organs
+/datum/species/proc/regenerate_organs(mob/living/carbon/C,datum/species/old_species,replace_current=TRUE)
+	var/obj/item/organ/brain/brain = C.getorganslot("brain")
+	var/obj/item/organ/heart/heart = C.getorganslot("heart")
+	var/obj/item/organ/lungs/lungs = C.getorganslot("lungs")
+	var/obj/item/organ/appendix/appendix = C.getorganslot("appendix")
+	var/obj/item/organ/eyes/eyes = C.getorganslot("eye_sight")
+	var/obj/item/organ/ears/ears = C.getorganslot("ears")
+	var/obj/item/organ/tongue/tongue = C.getorganslot("tongue")
+	var/obj/item/organ/liver/liver = C.getorganslot("liver")
+	var/obj/item/organ/stomach/stomach = C.getorganslot("stomach")
+
+	var/should_have_brain = TRUE
+	var/should_have_heart = !(NOBLOOD in species_traits)
+	var/should_have_lungs = !(NOBREATH in species_traits)
+	var/should_have_appendix = !(NOHUNGER in species_traits)
+	var/should_have_eyes = TRUE
+	var/should_have_ears = TRUE
+	var/should_have_tongue = TRUE
+	var/should_have_liver = !(NOLIVER in species_traits)
+	var/should_have_stomach = !(NOSTOMACH in species_traits)
+
+	if(brain && (replace_current || !should_have_brain))
+		if(!brain.decoy_override)//Just keep it if it's fake
+			brain.Remove(C,TRUE,TRUE)
+			QDEL_NULL(brain)
+	if(should_have_brain && !brain)
+		brain = new mutant_brain()
+		brain.Insert(C, TRUE, TRUE)
+
+	if(heart && (!should_have_heart || replace_current))
+		heart.Remove(C,1)
+		QDEL_NULL(heart)
+	if(should_have_heart && !heart)
+		heart = new()
+		heart.Insert(C)
+
+	if(lungs && (replace_current || !should_have_lungs))
+		lungs.Remove(C,1)
+		QDEL_NULL(lungs)
+	if(should_have_lungs && !lungs)
+		if(mutantlungs)
+			lungs = new mutantlungs()
+		else
+			lungs = new()
+		lungs.Insert(C)
+
+	if(liver && (!should_have_liver || replace_current))
+		liver.Remove(C,1)
+		QDEL_NULL(liver)
+	if(should_have_liver && !liver)
+		if(mutantliver)
+			liver = new mutantliver()
+		else
+			liver = new()
+		liver.Insert(C)
+
+	if(stomach && (!should_have_stomach || replace_current))
+		stomach.Remove(C,1)
+		QDEL_NULL(stomach)
+	if(should_have_stomach && !stomach)
+		if(mutantstomach)
+			stomach = new mutantstomach()
+		else
+			stomach = new()
+		stomach.Insert(C)
+
+	if(appendix && (!should_have_appendix || replace_current))
+		appendix.Remove(C,1)
+		QDEL_NULL(appendix)
+	if(should_have_appendix && !appendix)
+		appendix = new()
+		appendix.Insert(C)
+
+	if(C.get_bodypart("head"))
+		if(eyes && (replace_current || !should_have_eyes))
+			eyes.Remove(C,1)
+			QDEL_NULL(eyes)
+		if(should_have_eyes && !eyes)
+			eyes = new mutanteyes
+			eyes.Insert(C)
+
+		if(ears && (replace_current || !should_have_ears))
+			ears.Remove(C,1)
+			QDEL_NULL(ears)
+		if(should_have_ears && !ears)
+			ears = new mutantears
+			ears.Insert(C)
+
+		if(tongue && (replace_current || !should_have_tongue))
+			tongue.Remove(C,1)
+			QDEL_NULL(tongue)
+		if(should_have_tongue && !tongue)
+			tongue = new mutanttongue
+			tongue.Insert(C)
+
+	if(old_species)
+		for(var/mutantorgan in old_species.mutant_organs)
+			var/obj/item/organ/I = C.getorgan(mutantorgan)
+			if(I)
+				I.Remove(C)
+				QDEL_NULL(I)
+
+	for(var/path in mutant_organs)
+		var/obj/item/organ/I = new path()
+		I.Insert(C)
+
 /datum/species/proc/on_species_gain(mob/living/carbon/C, datum/species/old_species)
 	// Drop the items the new species can't wear
 	for(var/slot_id in no_equip)
@@ -138,79 +246,7 @@
 	if(DIGITIGRADE in species_traits)
 		C.Digitigrade_Leg_Swap(FALSE)
 
-	var/obj/item/organ/heart/heart = C.getorganslot("heart")
-	var/obj/item/organ/lungs/lungs = C.getorganslot("lungs")
-	var/obj/item/organ/appendix/appendix = C.getorganslot("appendix")
-	var/obj/item/organ/eyes/eyes = C.getorganslot("eye_sight")
-	var/obj/item/organ/ears/ears = C.getorganslot("ears")
-	var/obj/item/organ/tongue/tongue = C.getorganslot("tongue")
-
-	var/obj/item/organ/liver/liver = C.getorganslot("liver")
-	var/obj/item/organ/stomach/stomach = C.getorganslot("stomach")
-
-
-
-	if((NOBLOOD in species_traits) && heart)
-		heart.Remove(C)
-		qdel(heart)
-	else if((!(NOBLOOD in species_traits)) && (!heart))
-		heart = new()
-		heart.Insert(C)
-
-	if(lungs)
-		qdel(lungs)
-		lungs = null
-
-	QDEL_NULL(liver)
-
-	QDEL_NULL(stomach)
-
-	if(C.get_bodypart("head"))
-		if(eyes)
-			qdel(eyes)
-			eyes = new mutanteyes
-			eyes.Insert(C)
-
-		if(ears)
-			qdel(ears)
-			ears = new mutantears
-			ears.Insert(C)
-
-		if(tongue)
-			qdel(tongue)
-			tongue = new mutanttongue
-			tongue.Insert(C)
-
-	if((!(NOBREATH in species_traits)) && !lungs)
-		if(mutantlungs)
-			lungs = new mutantlungs()
-		else
-			lungs = new()
-		lungs.Insert(C)
-
-	if((!(NOLIVER in species_traits)) && (!liver))
-		if(mutantliver)
-			liver = new mutantliver()
-		else
-			liver = new()
-		liver.Insert(C)
-
-	if((!(NOSTOMACH in species_traits)) && (!stomach))
-		if(mutantstomach)
-			stomach = new mutantstomach()
-		else
-			stomach = new()
-		stomach.Insert(C)
-
-	if((NOHUNGER in species_traits) && appendix)
-		qdel(appendix)
-	else if((!(NOHUNGER in species_traits)) && (!appendix))
-		appendix = new()
-		appendix.Insert(C)
-
-	for(var/path in mutant_organs)
-		var/obj/item/organ/I = new path()
-		I.Insert(C)
+	regenerate_organs(C,old_species)		
 
 	if(exotic_bloodtype && C.dna.blood_type != exotic_bloodtype)
 		C.dna.blood_type = exotic_bloodtype
diff --git a/code/modules/mob/living/carbon/human/species_types/skeletons.dm b/code/modules/mob/living/carbon/human/species_types/skeletons.dm
index 4302c43ff8..be03e591aa 100644
--- a/code/modules/mob/living/carbon/human/species_types/skeletons.dm
+++ b/code/modules/mob/living/carbon/human/species_types/skeletons.dm
@@ -1,13 +1,13 @@
-/datum/species/skeleton
-	// 2spooky
-	name = "Spooky Scary Skeleton"
-	id = "skeleton"
-	say_mod = "rattles"
-	blacklisted = 1
-	sexes = 0
-	meat = /obj/item/reagent_containers/food/snacks/meat/slab/human/mutant/skeleton
-	species_traits = list(NOBREATH,RESISTHOT,RESISTCOLD,RESISTPRESSURE,NOBLOOD,RADIMMUNE,VIRUSIMMUNE,PIERCEIMMUNE,NOHUNGER,EASYDISMEMBER,EASYLIMBATTACHMENT)
-	mutant_organs = list(/obj/item/organ/tongue/bone)
-	damage_overlay_type = ""//let's not show bloody wounds or burns over bones.
-	disliked_food = NONE
-	liked_food = NONE
+/datum/species/skeleton
+	// 2spooky
+	name = "Spooky Scary Skeleton"
+	id = "skeleton"
+	say_mod = "rattles"
+	blacklisted = 1
+	sexes = 0
+	meat = /obj/item/reagent_containers/food/snacks/meat/slab/human/mutant/skeleton
+	species_traits = list(NOBREATH,RESISTHOT,RESISTCOLD,RESISTPRESSURE,NOBLOOD,RADIMMUNE,VIRUSIMMUNE,PIERCEIMMUNE,NOHUNGER,EASYDISMEMBER,EASYLIMBATTACHMENT)
+	mutanttongue = /obj/item/organ/tongue/bone
+	damage_overlay_type = ""//let's not show bloody wounds or burns over bones.
+	disliked_food = NONE
+	liked_food = NONE
diff --git a/code/modules/mob/living/carbon/human/species_types/zombies.dm b/code/modules/mob/living/carbon/human/species_types/zombies.dm
index 04123102c0..4ce8570c2b 100644
--- a/code/modules/mob/living/carbon/human/species_types/zombies.dm
+++ b/code/modules/mob/living/carbon/human/species_types/zombies.dm
@@ -9,7 +9,7 @@
 	blacklisted = 1
 	meat = /obj/item/reagent_containers/food/snacks/meat/slab/human/mutant/zombie
 	species_traits = list(NOBREATH,RESISTCOLD,RESISTPRESSURE,NOBLOOD,RADIMMUNE,NOZOMBIE,EASYDISMEMBER,EASYLIMBATTACHMENT,NOTRANSSTING)
-	mutant_organs = list(/obj/item/organ/tongue/zombie)
+	mutanttongue = /obj/item/organ/tongue/zombie
 	var/static/list/spooks = list('sound/hallucinations/growl1.ogg','sound/hallucinations/growl2.ogg','sound/hallucinations/growl3.ogg','sound/hallucinations/veryfar_noise.ogg','sound/hallucinations/wail.ogg')
 	disliked_food = NONE
 	liked_food = NONE
@@ -64,6 +64,6 @@
 	limbs_id = "zombie" //They look like zombies
 	sexes = 0
 	meat = /obj/item/reagent_containers/food/snacks/meat/slab/human/mutant/zombie
-	mutant_organs = list(/obj/item/organ/tongue/zombie)
+	mutanttongue = /obj/item/organ/tongue/zombie
 
 #undef REGENERATION_DELAY
diff --git a/code/modules/surgery/organs/organ_internal.dm b/code/modules/surgery/organs/organ_internal.dm
index f5a00d24cb..4fdda7a7bc 100644
--- a/code/modules/surgery/organs/organ_internal.dm
+++ b/code/modules/surgery/organs/organ_internal.dm
@@ -10,6 +10,8 @@
 	var/slot
 	// DO NOT add slots with matching names to different zones - it will break internal_organs_slot list!
 	var/vital = 0
+	//Was this organ implanted/inserted/etc, if true will not be removed during species change.
+	var/external = FALSE
 
 
 /obj/item/organ/proc/Insert(mob/living/carbon/M, special = 0, drop_if_replaced = TRUE)