diff --git a/code/modules/mob/living/carbon/human/update_icons.dm b/code/modules/mob/living/carbon/human/update_icons.dm
index 8dff1863061..0265723daed 100644
--- a/code/modules/mob/living/carbon/human/update_icons.dm
+++ b/code/modules/mob/living/carbon/human/update_icons.dm
@@ -110,63 +110,16 @@ Please contact me on #coderbus IRC. ~Carn x
 	var/icon/skeleton
 	var/list/cached_standing_overlays = list() // List of everything currently in a human's actual overlays
 
-//UPDATES OVERLAYS FROM OVERLAYS_LYING/OVERLAYS_STANDING
-//this proc is messy as I was forced to include some old laggy cloaking code to it so that I don't break cloakers
-//I'll work on removing that stuff by rewriting some of the cloaking stuff at a later date.
-/mob/living/carbon/human/update_icons()
-	var/stealth = 0
-	var/obj/item/clothing/suit/armor/abductor/vest/V // Begin the most snowflakey bullshit code I've ever written. I'm so sorry, but there was no other way.
+/mob/living/carbon/human/proc/apply_overlay(cache_index)
+	if((. = overlays_standing[cache_index]))
+		add_overlay(.)
 
-	for(V in list(wear_suit))
-		if(V.stealth_active)
-			stealth = 1
-			break
+/mob/living/carbon/human/proc/remove_overlay(cache_index)
+	var/I = overlays_standing[cache_index]
+	if(I)
+		cut_overlay(I)
+		overlays_standing[cache_index] = null
 
-	if(stealth)
-		icon = V.disguise.icon //if the suit is active, reference the suit's current loaded icon and overlays; this does not include hand overlays
-		overlays.Cut()
-		cached_standing_overlays.Cut() // Make sure the cache gets rebuilt once the disguise is gone
-
-		for(var/thing in V.disguise.overlays)
-			if(thing)
-				overlays += thing
-
-		var/image/I  = overlays_standing[L_HAND_LAYER] //manually add both left and right hand, so its independently updated
-		if(istype(I))
-			overlays += I
-		I = overlays_standing[R_HAND_LAYER]
-		if(istype(I))
-			overlays += I
-	else
-		icon = stand_icon
-		var/list/new_overlays = list()
-		var/list/old_overlays = cached_standing_overlays
-
-		// Totally regenerate if something touched our overlays
-		if(overlays.len != old_overlays.len)
-			overlays.Cut()
-			old_overlays.Cut()
-
-		for(var/i in 1 to TOTAL_LAYERS)
-			var/image/I = overlays_standing[i]
-			if(I)
-				if(istype(I))
-					// Since we avoid full overlay rebuilds, we have to reorganize the layers manually
-					I.layer = (-2 - (TOTAL_LAYERS - i)) // Highest layer gets -2, each prior layer is 1 lower
-				new_overlays += I
-
-		update_misc_effects()
-		if(misc_effect_overlays)
-			new_overlays += misc_effect_overlays
-
-		if(frozen) // Admin freeze overlay
-			new_overlays += frozen
-
-		overlays += (new_overlays - old_overlays)
-		overlays -= (old_overlays - new_overlays)
-		cached_standing_overlays = new_overlays
-
-	update_transform()
 
 var/global/list/damage_icon_parts = list()
 
@@ -185,9 +138,8 @@ var/global/list/damage_icon_parts = list()
 
 	previous_damage_appearance = damage_appearance
 
-	var/icon/standing = new /icon(dna.species.damage_overlays, "00")
-
-	var/image/standing_image = new /image("icon" = standing)
+	remove_overlay(H_DAMAGE_LAYER)
+	var/mutable_appearance/standing_image = mutable_appearance(dna.species.damage_overlays, "00", layer = H_DAMAGE_LAYER)
 
 	// blend the individual damage states with our icons
 	for(var/obj/item/organ/external/O in bodyparts)
@@ -205,13 +157,12 @@ var/global/list/damage_icon_parts = list()
 			DI = damage_icon_parts[cache_index]
 		standing_image.overlays += DI
 
-	overlays_standing[H_DAMAGE_LAYER]	= standing_image
+	overlays_standing[H_DAMAGE_LAYER] = standing_image
+	apply_overlay(H_DAMAGE_LAYER)
 
-	if(update_icons)   update_icons()
 
 //BASE MOB SPRITE
 /mob/living/carbon/human/proc/update_body(var/update_icons=1, var/rebuild_base=0)
-
 	var/husk_color_mod = rgb(96,88,80)
 	var/hulk_color_mod = rgb(48,224,40)
 
@@ -228,7 +179,8 @@ var/global/list/damage_icon_parts = list()
 	//Create a new, blank icon for our mob to use.
 	if(stand_icon)
 		qdel(stand_icon)
-	stand_icon = new(dna.species.icon_template ? dna.species.icon_template : 'icons/mob/human.dmi',"blank")
+
+	stand_icon = new(dna.species.icon_template ? dna.species.icon_template : 'icons/mob/human.dmi', "blank")
 	var/icon_key = ""
 	var/obj/item/organ/internal/eyes/eyes = get_int_organ(/obj/item/organ/internal/eyes)
 
@@ -307,14 +259,15 @@ var/global/list/damage_icon_parts = list()
 		human_icon_cache[icon_key] = base_icon
 
 	//END CACHED ICON GENERATION.
-	stand_icon.Blend(base_icon,ICON_OVERLAY)
+	stand_icon.Blend(base_icon, ICON_OVERLAY)
 	if((!body_accessory || istype(body_accessory, /datum/body_accessory/tail)) && dna.species.bodyflags & TAIL_OVERLAPPED) // If the user's species is flagged to have a tail that needs to be overlapped by limbs... (having a non-tail body accessory like the snake body will override this)
-		overlays_standing[LIMBS_LAYER]	= image(stand_icon) // Diverts limbs to their own layer so they can overlay things (i.e. tails).
+		overlays_standing[LIMBS_LAYER] = mutable_appearance(stand_icon, layer = LIMBS_LAYER) // Diverts limbs to their own layer so they can overlay things (i.e. tails).
+		apply_overlay(LIMBS_LAYER)
 	else
-		overlays_standing[LIMBS_LAYER] = null // So we don't get the old species' sprite splatted on top of the new one's
+		remove_overlay(LIMBS_LAYER) // So we don't get the old species' sprite splatted on top of the new one's
 
 	//Underwear
-	overlays_standing[UNDERWEAR_LAYER]	= null
+	remove_overlay(UNDERWEAR_LAYER)
 	var/icon/underwear_standing = new/icon('icons/mob/underwear.dmi',"nude")
 
 	if(underwear && dna.species.clothing_flags & HAS_UNDERWEAR)
@@ -334,16 +287,13 @@ var/global/list/damage_icon_parts = list()
 			underwear_standing.Blend(new /icon(U3.icon, "sk_[U3.icon_state]_s"), ICON_OVERLAY)
 
 	if(underwear_standing)
-		overlays_standing[UNDERWEAR_LAYER]	= image(underwear_standing)
+		overlays_standing[UNDERWEAR_LAYER]	= mutable_appearance(underwear_standing, layer = UNDERWEAR_LAYER)
 
-
-	if(update_icons)
-		update_icons()
+	apply_overlay(UNDERWEAR_LAYER)
 
 	if(lip_style  && (LIPS in dna.species.species_traits))
-		var/icon/lips = icon("icon"='icons/mob/human_face.dmi', "icon_state"="lips_[lip_style]_s")
+		var/icon/lips = icon("icon" = 'icons/mob/human_face.dmi', "icon_state" = "lips_[lip_style]_s")
 		lips.Blend(lip_color, ICON_ADD)
-
 		stand_icon.Blend(lips, ICON_OVERLAY)
 
 	//tail
@@ -360,10 +310,10 @@ var/global/list/damage_icon_parts = list()
 //MARKINGS OVERLAY
 /mob/living/carbon/human/proc/update_markings(var/update_icons=1)
 	//Reset our markings.
-	overlays_standing[MARKINGS_LAYER]	= null
+	remove_overlay(MARKINGS_LAYER)
 
 	//Base icon.
-	var/icon/markings_standing	= new/icon('icons/mob/body_accessory.dmi',"accessory_none_s")
+	var/icon/markings_standing = icon("icon" = 'icons/mob/body_accessory.dmi', "icon_state" = "accessory_none_s")
 
 	//Body markings.
 	var/obj/item/organ/external/chest/chest_organ = get_organ("chest")
@@ -371,7 +321,7 @@ var/global/list/damage_icon_parts = list()
 		var/body_marking = m_styles["body"]
 		var/datum/sprite_accessory/body_marking_style = GLOB.marking_styles_list[body_marking]
 		if(body_marking_style && body_marking_style.species_allowed && (dna.species.name in body_marking_style.species_allowed))
-			var/icon/b_marking_s = new/icon("icon" = body_marking_style.icon, "icon_state" = "[body_marking_style.icon_state]_s")
+			var/icon/b_marking_s = icon("icon" = body_marking_style.icon, "icon_state" = "[body_marking_style.icon_state]_s")
 			if(body_marking_style.do_colouration)
 				b_marking_s.Blend(m_colours["body"], ICON_ADD)
 			markings_standing.Blend(b_marking_s, ICON_OVERLAY)
@@ -381,33 +331,30 @@ var/global/list/damage_icon_parts = list()
 		var/head_marking = m_styles["head"]
 		var/datum/sprite_accessory/head_marking_style = GLOB.marking_styles_list[head_marking]
 		if(head_marking_style && head_marking_style.species_allowed && (head_organ.dna.species.name in head_marking_style.species_allowed))
-			var/icon/h_marking_s = new/icon("icon" = head_marking_style.icon, "icon_state" = "[head_marking_style.icon_state]_s")
+			var/icon/h_marking_s = icon("icon" = head_marking_style.icon, "icon_state" = "[head_marking_style.icon_state]_s")
 			if(head_marking_style.do_colouration)
 				h_marking_s.Blend(m_colours["head"], ICON_ADD)
 			markings_standing.Blend(h_marking_s, ICON_OVERLAY)
 
-	overlays_standing[MARKINGS_LAYER]	= image(markings_standing)
-
-	if(update_icons)   update_icons()
+	overlays_standing[MARKINGS_LAYER] = mutable_appearance(markings_standing, layer = MARKINGS_LAYER)
+	apply_overlay(MARKINGS_LAYER)
 
 //HEAD ACCESSORY OVERLAY
 /mob/living/carbon/human/proc/update_head_accessory(var/update_icons=1)
 	//Reset our head accessory
-	overlays_standing[HEAD_ACCESSORY_LAYER]	= null
-	overlays_standing[HEAD_ACC_OVER_LAYER]	= null
+	remove_overlay(HEAD_ACCESSORY_LAYER)
+	remove_overlay(HEAD_ACC_OVER_LAYER)
 
 	var/obj/item/organ/external/head/head_organ = get_organ("head")
 	if(!head_organ)
-		if(update_icons)   update_icons()
 		return
 
 	//masks and helmets can obscure our head accessory
 	if((head && (head.flags & BLOCKHAIR)) || (wear_mask && (wear_mask.flags & BLOCKHAIR)))
-		if(update_icons)   update_icons()
 		return
 
 	//base icons
-	var/icon/head_accessory_standing	= new /icon('icons/mob/body_accessory.dmi',"accessory_none_s")
+	var/icon/head_accessory_standing = new /icon('icons/mob/body_accessory.dmi',"accessory_none_s")
 	if(head_organ.ha_style && (head_organ.dna.species.bodyflags & HAS_HEAD_ACCESSORY))
 		var/datum/sprite_accessory/head_accessory/head_accessory_style = GLOB.head_accessory_styles_list[head_organ.ha_style]
 		if(head_accessory_style && head_accessory_style.species_allowed)
@@ -419,38 +366,33 @@ var/global/list/damage_icon_parts = list()
 														   //Having it this way preserves animations. Useful for animated antennae.
 
 				if(head_accessory_style.over_hair) //Select which layer to use based on the properties of the head accessory style.
-					overlays_standing[HEAD_ACC_OVER_LAYER]	= image(head_accessory_standing)
+					overlays_standing[HEAD_ACC_OVER_LAYER] = mutable_appearance(head_accessory_standing, layer = HEAD_ACC_OVER_LAYER)
+					apply_overlay(HEAD_ACC_OVER_LAYER)
 				else
-					overlays_standing[HEAD_ACCESSORY_LAYER] = image(head_accessory_standing)
+					overlays_standing[HEAD_ACCESSORY_LAYER] = mutable_appearance(head_accessory_standing, layer = HEAD_ACCESSORY_LAYER)
+					apply_overlay(HEAD_ACCESSORY_LAYER)
 		else
 			//warning("Invalid ha_style for [species.name]: [ha_style]")
 
-	if(update_icons)   update_icons()
 
 
 //HAIR OVERLAY
 /mob/living/carbon/human/proc/update_hair(var/update_icons=1)
 	//Reset our hair
-	overlays_standing[HAIR_LAYER] = null
+	remove_overlay(HAIR_LAYER)
 
 	var/obj/item/organ/external/head/head_organ = get_organ("head")
 	if(!head_organ)
-		if(update_icons)   update_icons()
 		return
 
 	//masks and helmets can obscure our hair, unless we're a synthetic
 	if((head && (head.flags & BLOCKHAIR)) || (wear_mask && (wear_mask.flags & BLOCKHAIR)))
-		if(update_icons)   update_icons()
 		return
 
 	//base icons
 	var/icon/hair_standing	= new /icon('icons/mob/human_face.dmi',"bald_s")
-	//var/icon/debrained_s = new /icon("icon"='icons/mob/human_face.dmi', "icon_state" = "debrained_s")
-
 	if(head_organ.h_style && !(head && (head.flags & BLOCKHEADHAIR) && !(isSynthetic())))
 		var/datum/sprite_accessory/hair/hair_style = GLOB.hair_styles_full_list[head_organ.h_style]
-		//if(!src.get_int_organ(/obj/item/organ/internal/brain) && !ismachine(src))//make it obvious we have NO BRAIN
-		//	hair_standing.Blend(debrained_s, ICON_OVERLAY)
 		if(hair_style && hair_style.species_allowed)
 			if((head_organ.dna.species.name in hair_style.species_allowed) || (head_organ.dna.species.bodyflags & ALL_RPARTS)) //If the head's species is in the list of allowed species for the hairstyle, or the head's species is one flagged to have bodies comprised wholly of cybernetics...
 				var/icon/hair_s = new/icon("icon" = hair_style.icon, "icon_state" = "[hair_style.icon_state]_s")
@@ -471,30 +413,26 @@ var/global/list/damage_icon_parts = list()
 			//warning("Invalid h_style for [species.name]: [h_style]")
 		//hair_standing.Blend(debrained_s, ICON_OVERLAY)//how does i overlay for fish?
 
-	overlays_standing[HAIR_LAYER] = image(hair_standing)
-
-	if(update_icons)   update_icons()
+	overlays_standing[HAIR_LAYER] = mutable_appearance(hair_standing, layer = HAIR_LAYER)
+	apply_overlay(HAIR_LAYER)
 
 
 //FACIAL HAIR OVERLAY
 /mob/living/carbon/human/proc/update_fhair(var/update_icons=1)
 	//Reset our facial hair
-	overlays_standing[FHAIR_LAYER]		= null
-	overlays_standing[FHAIR_OVER_LAYER]	= null
+	remove_overlay(FHAIR_LAYER)
+	remove_overlay(FHAIR_OVER_LAYER)
 
 	var/obj/item/organ/external/head/head_organ = get_organ("head")
 	if(!head_organ)
-		if(update_icons)   update_icons()
 		return
 
 	//masks and helmets can obscure our facial hair, unless we're a synthetic
 	if((head && (head.flags & BLOCKHAIR)) || (wear_mask && (wear_mask.flags & BLOCKHAIR)))
-		if(update_icons)   update_icons()
 		return
 
 	//base icons
 	var/icon/face_standing	= new /icon('icons/mob/human_face.dmi',"bald_s")
-
 	if(head_organ.f_style)
 		var/datum/sprite_accessory/facial_hair/facial_hair_style = GLOB.facial_hair_styles_list[head_organ.f_style]
 		if(facial_hair_style && facial_hair_style.species_allowed)
@@ -514,46 +452,49 @@ var/global/list/damage_icon_parts = list()
 				face_standing.Blend(facial_s, ICON_OVERLAY)
 
 				if(facial_hair_style.over_hair) //Select which layer to use based on the properties of the facial hair style.
-					overlays_standing[FHAIR_OVER_LAYER] = image(face_standing)
+					overlays_standing[FHAIR_OVER_LAYER] = mutable_appearance(face_standing, layer = FHAIR_OVER_LAYER)
+					apply_overlay(FHAIR_OVER_LAYER)
 				else
-					overlays_standing[FHAIR_LAYER] = image(face_standing)
+					overlays_standing[FHAIR_LAYER] = mutable_appearance(face_standing, layer = FHAIR_LAYER)
+					apply_overlay(FHAIR_LAYER)
 		else
 			//warning("Invalid f_style for [species.name]: [f_style]")
 
-	if(update_icons)   update_icons()
+	
 
 /mob/living/carbon/human/update_mutations(var/update_icons=1)
+	remove_overlay(MUTATIONS_LAYER)
 	var/fat
 	if(FAT in mutations)
 		fat = "fat"
 
-	var/image/standing	= image("icon" = 'icons/effects/genetics.dmi')
+	var/mutable_appearance/standing = mutable_appearance('icons/effects/genetics.dmi', layer = MUTATIONS_LAYER)
 	var/add_image = 0
 	var/g = "m"
-	if(gender == FEMALE)	g = "f"
+	if(gender == FEMALE)
+		g = "f"
 	// DNA2 - Drawing underlays.
 	for(var/datum/dna/gene/gene in dna_genes)
 		if(!gene.block)
 			continue
 		if(gene.is_active(src))
-			var/underlay=gene.OnDrawUnderlays(src,g,fat)
+			var/underlay = gene.OnDrawUnderlays(src, g, fat)
 			if(underlay)
 				standing.underlays += underlay
 				add_image = 1
 	for(var/mut in mutations)
 		switch(mut)
 			if(LASER)
-				standing.overlays	+= "lasereyes_s"
+				standing.overlays += "lasereyes_s"
 				add_image = 1
 	if((COLDRES in mutations) && (HEATRES in mutations))
-		standing.underlays	-= "cold[fat]_s"
-		standing.underlays	-= "fire[fat]_s"
-		standing.underlays	+= "coldfire[fat]_s"
+		standing.underlays -= "cold[fat]_s"
+		standing.underlays -= "fire[fat]_s"
+		standing.underlays += "coldfire[fat]_s"
+
 	if(add_image)
-		overlays_standing[MUTATIONS_LAYER]	= standing
-	else
-		overlays_standing[MUTATIONS_LAYER]	= null
-	if(update_icons)   update_icons()
+		overlays_standing[MUTATIONS_LAYER] = standing
+	apply_overlay(MUTATIONS_LAYER)
 
 
 /mob/living/carbon/human/proc/update_mutantrace(var/update_icons=1)
@@ -566,17 +507,14 @@ var/global/list/damage_icon_parts = list()
 
 	update_hair(0)
 	update_fhair(0)
-	if(update_icons)   update_icons()
 
 
 /mob/living/carbon/human/update_fire()
+	remove_overlay(FIRE_LAYER)
 	if(on_fire)
 		if(!overlays_standing[FIRE_LAYER])
-			overlays_standing[FIRE_LAYER] = image("icon"=fire_dmi, "icon_state"=fire_sprite)
-			update_icons()
-	else
-		overlays_standing[FIRE_LAYER] = null
-		update_icons()
+			overlays_standing[FIRE_LAYER] = mutable_appearance(fire_dmi, fire_sprite, layer = FIRE_LAYER)
+	apply_overlay(FIRE_LAYER)
 
 /* --------------------------------------- */
 //For legacy support.
@@ -617,7 +555,7 @@ var/global/list/damage_icon_parts = list()
 //vvvvvv UPDATE_INV PROCS vvvvvv
 
 /mob/living/carbon/human/update_inv_w_uniform(var/update_icons=1)
-
+	remove_overlay(UNIFORM_LAYER)
 	if(client && hud_used)
 		var/obj/screen/inventory/inv = hud_used.inv_slots[slot_w_uniform]
 		if(inv)
@@ -630,9 +568,10 @@ var/global/list/damage_icon_parts = list()
 			client.screen += w_uniform				//Either way, add the item to the HUD
 
 		var/t_color = w_uniform.item_color
-		if(!t_color)		t_color = icon_state
-		var/image/standing	= image("icon_state" = "[t_color]_s")
+		if(!t_color)
+			t_color = icon_state
 
+		var/mutable_appearance/standing = mutable_appearance('icons/mob/uniform.dmi', "[t_color]_s", layer = UNIFORM_LAYER)
 		if(FAT in mutations)
 			if(w_uniform.flags_size & ONESIZEFITSALL)
 				standing.icon	= 'icons/mob/uniform_fat.dmi'
@@ -640,8 +579,6 @@ var/global/list/damage_icon_parts = list()
 				to_chat(src, "<span class='warning'>You burst out of \the [w_uniform]!</span>")
 				unEquip(w_uniform)
 				return
-		else
-			standing.icon	= 'icons/mob/uniform.dmi'
 
 		if(w_uniform.icon_override)
 			standing.icon = w_uniform.icon_override
@@ -650,13 +587,14 @@ var/global/list/damage_icon_parts = list()
 
 		if(w_uniform.blood_DNA)
 			var/image/bloodsies	= image("icon" = dna.species.blood_mask, "icon_state" = "uniformblood")
-			bloodsies.color		= w_uniform.blood_color
-			standing.overlays	+= bloodsies
+			bloodsies.color = w_uniform.blood_color
+			standing.overlays += bloodsies
 
-		if(w_uniform:accessories.len)	//WE CHECKED THE TYPE ABOVE. THIS REALLY SHOULD BE FINE.
+		if(w_uniform:accessories.len)	//WE CHECKED THE TYPE ABOVE. THIS REALLY SHOULD BE FINE. // oh my god kys whoever made this if statement jfc :gun:
 			for(var/obj/item/clothing/accessory/A in w_uniform:accessories)
 				var/tie_color = A.item_color
-				if(!tie_color) tie_color = A.icon_state
+				if(!tie_color)
+					tie_color = A.icon_state
 				if(A.icon_override)
 					standing.overlays += image("icon" = A.icon_override, "icon_state" = "[A.icon_state]")
 				else if(A.sprite_sheets && A.sprite_sheets[dna.species.name])
@@ -664,25 +602,24 @@ var/global/list/damage_icon_parts = list()
 				else
 					standing.overlays += image("icon" = 'icons/mob/ties.dmi', "icon_state" = "[tie_color]")
 
-		overlays_standing[UNIFORM_LAYER]	= standing
+		overlays_standing[UNIFORM_LAYER] = standing
 	else
-		overlays_standing[UNIFORM_LAYER]	= null
 		// Automatically drop anything in store / id / belt if you're not wearing a uniform.	//CHECK IF NECESARRY
-		for( var/obj/item/thing in list(r_store, l_store, wear_id, wear_pda, belt) )						//
-			if(thing)																			//
-				unEquip(thing)																	//
-				if(client)																		//
-					client.screen -= thing														//
-																								//
+		for(var/obj/item/thing in list(r_store, l_store, wear_id, wear_pda, belt))				// whoever made this
+			if(thing)																			// you're a piece of fucking garbage
+				unEquip(thing)																	// why the fuck would you goddamn do this motherfucking shit
+				if(client)																		// INVENTORY CODE IN FUCKING ICON CODE
+					client.screen -= thing														// WHAT THE FUCKING FUCK BAY GODDAMNIT
+																								// **I FUCKING HATE YOU AAAAAAAAAA**
 				if(thing)																		//
 					thing.loc = loc																//
 					thing.dropped(src)															//
 					thing.layer = initial(thing.layer)
 					thing.plane = initial(thing.plane)
-	if(update_icons)   update_icons()
+	apply_overlay(UNIFORM_LAYER)
 
 /mob/living/carbon/human/update_inv_wear_id(var/update_icons=1)
-
+	remove_overlay(ID_LAYER)
 	if(client && hud_used)
 		var/obj/screen/inventory/inv = hud_used.inv_slots[slot_wear_id]
 		if(inv)
@@ -694,16 +631,11 @@ var/global/list/damage_icon_parts = list()
 			client.screen += wear_id
 
 		if(w_uniform && w_uniform:displays_id)
-			overlays_standing[ID_LAYER]	= image("icon" = 'icons/mob/mob.dmi', "icon_state" = "id")
-		else
-			overlays_standing[ID_LAYER]	= null
-	else
-		overlays_standing[ID_LAYER]	= null
-
-	if(update_icons)   update_icons()
+			overlays_standing[ID_LAYER]	= mutable_appearance('icons/mob/mob.dmi', "id", layer = ID_LAYER)
+	apply_overlay(ID_LAYER)
 
 /mob/living/carbon/human/update_inv_gloves(var/update_icons=1)
-
+	remove_overlay(GLOVES_LAYER)
 	if(client && hud_used)
 		var/obj/screen/inventory/inv = hud_used.inv_slots[slot_gloves]
 		if(inv)
@@ -718,32 +650,30 @@ var/global/list/damage_icon_parts = list()
 		var/t_state = gloves.item_state
 		if(!t_state)	t_state = gloves.icon_state
 
-		var/image/standing
+		var/mutable_appearance/standing
 		if(gloves.icon_override)
-			standing = image("icon" = gloves.icon_override, "icon_state" = "[t_state]")
+			standing = mutable_appearance(gloves.icon_override, "[t_state]", layer = GLOVES_LAYER)
 		else if(gloves.sprite_sheets && gloves.sprite_sheets[dna.species.name])
-			standing = image("icon" = gloves.sprite_sheets[dna.species.name], "icon_state" = "[t_state]")
+			standing = mutable_appearance(gloves.sprite_sheets[dna.species.name], "[t_state]", layer = GLOVES_LAYER)
 		else
-			standing = image("icon" = 'icons/mob/hands.dmi', "icon_state" = "[t_state]")
+			standing = mutable_appearance('icons/mob/hands.dmi', "[t_state]", layer = GLOVES_LAYER)
 
 		if(gloves.blood_DNA)
 			var/image/bloodsies	= image("icon" = dna.species.blood_mask, "icon_state" = "bloodyhands")
 			bloodsies.color = gloves.blood_color
-			standing.overlays	+= bloodsies
+			standing.overlays += bloodsies
 		overlays_standing[GLOVES_LAYER]	= standing
 	else
 		if(blood_DNA)
-			var/image/bloodsies	= image("icon" = dna.species.blood_mask, "icon_state" = "bloodyhands")
+			var/mutable_appearance/bloodsies = mutable_appearance(dna.species.blood_mask, "bloodyhands", layer = GLOVES_LAYER)
 			bloodsies.color = hand_blood_color
 			overlays_standing[GLOVES_LAYER]	= bloodsies
-		else
-			overlays_standing[GLOVES_LAYER]	= null
-	if(update_icons)   update_icons()
+	apply_overlay(GLOVES_LAYER)
 
 
 /mob/living/carbon/human/update_inv_glasses(var/update_icons=1)
-	overlays_standing[GLASSES_LAYER] = null
-	overlays_standing[GLASSES_OVER_LAYER] = null
+	remove_overlay(GLASSES_LAYER)
+	remove_overlay(GLASSES_OVER_LAYER)
 
 	if(client && hud_used)
 		var/obj/screen/inventory/inv = hud_used.inv_slots[slot_glasses]
@@ -751,7 +681,7 @@ var/global/list/damage_icon_parts = list()
 			inv.update_icon()
 
 	if(glasses)
-		var/image/new_glasses
+		var/mutable_appearance/new_glasses
 		var/obj/item/organ/external/head/head_organ = get_organ("head")
 		if(client && hud_used && hud_used.hud_shown)
 			if(hud_used.inventory_shown)			//if the inventory is open ...
@@ -759,22 +689,23 @@ var/global/list/damage_icon_parts = list()
 			client.screen += glasses				//Either way, add the item to the HUD
 
 		if(glasses.icon_override)
-			new_glasses = image("icon" = glasses.icon_override, "icon_state" = "[glasses.icon_state]")
+			new_glasses = mutable_appearance(glasses.icon_override, "[glasses.icon_state]", layer = GLASSES_LAYER)
 		else if(glasses.sprite_sheets && glasses.sprite_sheets[head_organ.dna.species.name])
-			new_glasses = image("icon" = glasses.sprite_sheets[head_organ.dna.species.name], "icon_state" = "[glasses.icon_state]")
+			new_glasses = mutable_appearance(glasses.sprite_sheets[head_organ.dna.species.name], "[glasses.icon_state]", layer = GLASSES_LAYER)
 		else
-			new_glasses = image("icon" = 'icons/mob/eyes.dmi', "icon_state" = "[glasses.icon_state]")
+			new_glasses = mutable_appearance('icons/mob/eyes.dmi', "[glasses.icon_state]", layer = GLASSES_LAYER)
 
 		var/datum/sprite_accessory/hair/hair_style = GLOB.hair_styles_full_list[head_organ.h_style]
 		if(hair_style && hair_style.glasses_over) //Select which layer to use based on the properties of the hair style. Hair styles with hair that don't overhang the arms of the glasses should have glasses_over set to a positive value.
+			new_glasses.layer = -GLASSES_OVER_LAYER
 			overlays_standing[GLASSES_OVER_LAYER] = new_glasses
+			apply_overlay(GLASSES_OVER_LAYER)
 		else
 			overlays_standing[GLASSES_LAYER] = new_glasses
-
-	if(update_icons)   update_icons()
+			apply_overlay(GLASSES_LAYER)
 
 /mob/living/carbon/human/update_inv_ears(var/update_icons=1)
-
+	remove_overlay(EARS_LAYER)
 	if(client && hud_used)
 		var/obj/screen/inventory/inv = hud_used.inv_slots[slot_l_ear]
 		if(inv)
@@ -795,12 +726,12 @@ var/global/list/damage_icon_parts = list()
 			var/t_type = l_ear.icon_state
 			if(l_ear.icon_override)
 				t_type = "[t_type]_l"
-				overlays_standing[EARS_LAYER] = image("icon" = l_ear.icon_override, "icon_state" = "[t_type]")
+				overlays_standing[EARS_LAYER] = mutable_appearance(l_ear.icon_override, "[t_type]", layer = EARS_LAYER)
 			else if(l_ear.sprite_sheets && l_ear.sprite_sheets[dna.species.name])
 				t_type = "[t_type]_l"
-				overlays_standing[EARS_LAYER] = image("icon" = l_ear.sprite_sheets[dna.species.name], "icon_state" = "[t_type]")
+				overlays_standing[EARS_LAYER] = mutable_appearance(l_ear.sprite_sheets[dna.species.name], "[t_type]", layer = EARS_LAYER)
 			else
-				overlays_standing[EARS_LAYER] = image("icon" = 'icons/mob/ears.dmi', "icon_state" = "[t_type]")
+				overlays_standing[EARS_LAYER] = mutable_appearance('icons/mob/ears.dmi', "[t_type]", layer = EARS_LAYER)
 
 		if(r_ear)
 			if(client && hud_used && hud_used.hud_shown)
@@ -811,19 +742,16 @@ var/global/list/damage_icon_parts = list()
 			var/t_type = r_ear.icon_state
 			if(r_ear.icon_override)
 				t_type = "[t_type]_r"
-				overlays_standing[EARS_LAYER] = image("icon" = r_ear.icon_override, "icon_state" = "[t_type]")
+				overlays_standing[EARS_LAYER] = mutable_appearance(r_ear.icon_override, "[t_type]", layer = EARS_LAYER)
 			else if(r_ear.sprite_sheets && r_ear.sprite_sheets[dna.species.name])
 				t_type = "[t_type]_r"
-				overlays_standing[EARS_LAYER] = image("icon" = r_ear.sprite_sheets[dna.species.name], "icon_state" = "[t_type]")
+				overlays_standing[EARS_LAYER] = mutable_appearance(r_ear.sprite_sheets[dna.species.name], "[t_type]", layer = EARS_LAYER)
 			else
-				overlays_standing[EARS_LAYER] = image("icon" = 'icons/mob/ears.dmi', "icon_state" = "[t_type]")
-
-	else
-		overlays_standing[EARS_LAYER]	= null
-	if(update_icons)   update_icons()
+				overlays_standing[EARS_LAYER] = mutable_appearance('icons/mob/ears.dmi', "[t_type]", layer = EARS_LAYER)
+	apply_overlay(EARS_LAYER)
 
 /mob/living/carbon/human/update_inv_shoes(var/update_icons=1)
-
+	remove_overlay(SHOES_LAYER)
 	if(client && hud_used)
 		var/obj/screen/inventory/inv = hud_used.inv_slots[slot_shoes]
 		if(inv)
@@ -835,13 +763,13 @@ var/global/list/damage_icon_parts = list()
 				shoes.screen_loc = ui_shoes			//...draw the item in the inventory screen
 			client.screen += shoes					//Either way, add the item to the HUD
 
-		var/image/standing
+		var/mutable_appearance/standing
 		if(shoes.icon_override)
-			standing = image("icon" = shoes.icon_override, "icon_state" = "[shoes.icon_state]")
+			standing = mutable_appearance(shoes.icon_override, "[shoes.icon_state]", layer = SHOES_LAYER)
 		else if(shoes.sprite_sheets && shoes.sprite_sheets[dna.species.name])
-			standing = image("icon" = shoes.sprite_sheets[dna.species.name], "icon_state" = "[shoes.icon_state]")
+			standing = mutable_appearance(shoes.sprite_sheets[dna.species.name], "[shoes.icon_state]", layer = SHOES_LAYER)
 		else
-			standing = image("icon" = 'icons/mob/feet.dmi', "icon_state" = "[shoes.icon_state]")
+			standing = mutable_appearance('icons/mob/feet.dmi', "[shoes.icon_state]", layer = SHOES_LAYER)
 
 
 		if(shoes.blood_DNA)
@@ -851,15 +779,13 @@ var/global/list/damage_icon_parts = list()
 		overlays_standing[SHOES_LAYER] = standing
 	else
 		if(feet_blood_DNA)
-			var/image/bloodsies = image("icon" = dna.species.blood_mask, "icon_state" = "shoeblood")
+			var/mutable_appearance/bloodsies = mutable_appearance(dna.species.blood_mask, "shoeblood", layer = SHOES_LAYER)
 			bloodsies.color = feet_blood_color
 			overlays_standing[SHOES_LAYER] = bloodsies
-		else
-			overlays_standing[SHOES_LAYER] = null
-	if(update_icons)   update_icons()
+	apply_overlay(SHOES_LAYER)
 
 /mob/living/carbon/human/update_inv_s_store(var/update_icons=1)
-
+	remove_overlay(SUIT_STORE_LAYER)
 	if(client && hud_used)
 		var/obj/screen/inventory/inv = hud_used.inv_slots[slot_s_store]
 		if(inv)
@@ -874,42 +800,37 @@ var/global/list/damage_icon_parts = list()
 		if(!t_state)
 			t_state = s_store.icon_state
 		var/dmi='icons/mob/belt_mirror.dmi'
-		overlays_standing[SUIT_STORE_LAYER]  = image("icon" = dmi, "icon_state" = "[t_state]")
+		overlays_standing[SUIT_STORE_LAYER] = mutable_appearance(dmi, "[t_state]", layer = SUIT_STORE_LAYER)
 		s_store.screen_loc = ui_sstore1		//TODO
-	else
-		overlays_standing[SUIT_STORE_LAYER]	= null
-	if(update_icons)   update_icons()
+	apply_overlay(SUIT_STORE_LAYER)
 
 
 /mob/living/carbon/human/update_inv_head(var/update_icons=1)
 	..()
+	remove_overlay(HEAD_LAYER)
 	if(client && hud_used)
 		var/obj/screen/inventory/inv = hud_used.inv_slots[slot_head]
 		if(inv)
 			inv.update_icon()
 
 	if(head)
-		var/image/standing
+		var/mutable_appearance/standing
 		if(head.icon_override)
-			standing = image("icon" = head.icon_override, "icon_state" = "[head.icon_state]")
+			standing = mutable_appearance(head.icon_override, "[head.icon_state]", layer = HEAD_LAYER)
 		else if(head.sprite_sheets && head.sprite_sheets[dna.species.name])
-			standing = image("icon" = head.sprite_sheets[dna.species.name], "icon_state" = "[head.icon_state]")
+			standing = mutable_appearance(head.sprite_sheets[dna.species.name], "[head.icon_state]", layer = HEAD_LAYER)
 		else
-			standing = image("icon" = 'icons/mob/head.dmi', "icon_state" = "[head.icon_state]")
+			standing = mutable_appearance('icons/mob/head.dmi', "[head.icon_state]", layer = HEAD_LAYER)
 
 		if(head.blood_DNA)
 			var/image/bloodsies = image("icon" = dna.species.blood_mask, "icon_state" = "helmetblood")
 			bloodsies.color = head.blood_color
-			standing.overlays	+= bloodsies
-		overlays_standing[HEAD_LAYER]	= standing
-
-
-	else
-		overlays_standing[HEAD_LAYER]	= null
-	if(update_icons)   update_icons()
+			standing.overlays += bloodsies
+		overlays_standing[HEAD_LAYER] = standing
+	apply_overlay(HEAD_LAYER)
 
 /mob/living/carbon/human/update_inv_belt(var/update_icons=1)
-
+	remove_overlay(BELT_LAYER)
 	if(client && hud_used)
 		var/obj/screen/inventory/inv = hud_used.inv_slots[slot_belt]
 		if(inv)
@@ -921,21 +842,21 @@ var/global/list/damage_icon_parts = list()
 
 	if(belt)
 		var/t_state = belt.item_state
-		if(!t_state)	t_state = belt.icon_state
+		if(!t_state)
+			t_state = belt.icon_state
 
 		if(belt.icon_override)
 			t_state = "[t_state]_be"
-			overlays_standing[BELT_LAYER] = image("icon" = belt.icon_override, "icon_state" = "[t_state]")
+			overlays_standing[BELT_LAYER] = mutable_appearance(belt.icon_override, "[t_state]", layer = BELT_LAYER)
 		else if(belt.sprite_sheets && belt.sprite_sheets[dna.species.name])
-			overlays_standing[BELT_LAYER] = image("icon" = belt.sprite_sheets[dna.species.name], "icon_state" = "[t_state]")
+			overlays_standing[BELT_LAYER] = mutable_appearance(belt.sprite_sheets[dna.species.name], "[t_state]", layer = BELT_LAYER)
 		else
-			overlays_standing[BELT_LAYER] = image("icon" = 'icons/mob/belt.dmi', "icon_state" = "[t_state]")
-	else
-		overlays_standing[BELT_LAYER] = null
-	if(update_icons)   update_icons()
+			overlays_standing[BELT_LAYER] = mutable_appearance('icons/mob/belt.dmi', "[t_state]", layer = BELT_LAYER)
+	apply_overlay(BELT_LAYER)
 
 
 /mob/living/carbon/human/update_inv_wear_suit(var/update_icons=1)
+	remove_overlay(SUIT_LAYER)
 	if(client && hud_used)
 		var/obj/screen/inventory/inv = hud_used.inv_slots[slot_wear_suit]
 		if(inv)
@@ -947,47 +868,37 @@ var/global/list/damage_icon_parts = list()
 				wear_suit.screen_loc = ui_oclothing	//TODO	//...draw the item in the inventory screen
 			client.screen += wear_suit						//Either way, add the item to the HUD
 
-		var/image/standing
+		var/mutable_appearance/standing
 		if(wear_suit.icon_override)
-			standing = image("icon" = wear_suit.icon_override, "icon_state" = "[wear_suit.icon_state]")
+			standing = mutable_appearance(wear_suit.icon_override, "[wear_suit.icon_state]", layer = SUIT_LAYER)
 		else if(wear_suit.sprite_sheets && wear_suit.sprite_sheets[dna.species.name])
-			standing = image("icon" = wear_suit.sprite_sheets[dna.species.name], "icon_state" = "[wear_suit.icon_state]")
+			standing = mutable_appearance(wear_suit.sprite_sheets[dna.species.name], "[wear_suit.icon_state]", layer = SUIT_LAYER)
 		else if(FAT in mutations)
 			if(wear_suit.flags_size & ONESIZEFITSALL)
-				standing = image("icon" = 'icons/mob/suit_fat.dmi', "icon_state" = "[wear_suit.icon_state]")
+				standing = mutable_appearance('icons/mob/suit_fat.dmi', "[wear_suit.icon_state]", layer = SUIT_LAYER)
 			else
 				to_chat(src, "<span class='warning'>You burst out of \the [wear_suit]!</span>")
 				unEquip(wear_suit)
 				return
 		else
-			standing = image("icon" = 'icons/mob/suit.dmi', "icon_state" = "[wear_suit.icon_state]")
-
+			standing = mutable_appearance('icons/mob/suit.dmi', "[wear_suit.icon_state]", layer = SUIT_LAYER)
 
 		if(wear_suit.breakouttime)
 			drop_l_hand()
 			drop_r_hand()
 
-
 		if(wear_suit.blood_DNA)
 			var/obj/item/clothing/suit/S = wear_suit
 			var/image/bloodsies = image("icon" = dna.species.blood_mask, "icon_state" = "[S.blood_overlay_type]blood")
 			bloodsies.color = wear_suit.blood_color
-			standing.overlays	+= bloodsies
+			standing.overlays += bloodsies
 
+		overlays_standing[SUIT_LAYER] = standing
 
-		overlays_standing[SUIT_LAYER]	= standing
-
-		update_tail_layer(0)
-
-	else
-		overlays_standing[SUIT_LAYER]	= null
-
-		update_tail_layer(0)
-
+	apply_overlay(SUIT_LAYER)
+	update_tail_layer(0)
 	update_collar(0)
 
-	if(update_icons)   update_icons()
-
 /mob/living/carbon/human/update_inv_pockets()
 	if(client && hud_used)
 		var/obj/screen/inventory/inv
@@ -1021,6 +932,7 @@ var/global/list/damage_icon_parts = list()
 
 /mob/living/carbon/human/update_inv_wear_mask(var/update_icons = 1)
 	..()
+	remove_overlay(FACEMASK_LAYER)
 	if(client && hud_used)
 		var/obj/screen/inventory/inv = hud_used.inv_slots[slot_wear_mask]
 		if(inv)
@@ -1031,107 +943,94 @@ var/global/list/damage_icon_parts = list()
 		if(head_organ.alt_head && head_organ.alt_head != "None")
 			alternate_head = GLOB.alt_heads_list[head_organ.alt_head]
 
-		var/image/standing
+		var/mutable_appearance/standing
 		var/icon/mask_icon = new(wear_mask.icon)
 		if(wear_mask.icon_override)
 			mask_icon = new(wear_mask.icon_override)
-			standing = image("icon" = wear_mask.icon_override, "icon_state" = "[wear_mask.icon_state][(alternate_head && ("[wear_mask.icon_state]_[alternate_head.suffix]" in mask_icon.IconStates())) ? "_[alternate_head.suffix]" : ""]")
+			standing = mutable_appearance(wear_mask.icon_override, "[wear_mask.icon_state][(alternate_head && ("[wear_mask.icon_state]_[alternate_head.suffix]" in mask_icon.IconStates())) ? "_[alternate_head.suffix]" : ""]", layer = FACEMASK_LAYER)
 		else if(wear_mask.sprite_sheets && wear_mask.sprite_sheets[dna.species.name])
 			mask_icon = new(wear_mask.sprite_sheets[dna.species.name])
-			standing = image("icon" = wear_mask.sprite_sheets[dna.species.name], "icon_state" = "[wear_mask.icon_state][(alternate_head && ("[wear_mask.icon_state]_[alternate_head.suffix]" in mask_icon.IconStates())) ? "_[alternate_head.suffix]" : ""]")
+			standing = mutable_appearance(wear_mask.sprite_sheets[dna.species.name], "[wear_mask.icon_state][(alternate_head && ("[wear_mask.icon_state]_[alternate_head.suffix]" in mask_icon.IconStates())) ? "_[alternate_head.suffix]" : ""]", layer = FACEMASK_LAYER)
 		else
-			standing = image("icon" = 'icons/mob/mask.dmi', "icon_state" = "[wear_mask.icon_state][(alternate_head && ("[wear_mask.icon_state]_[alternate_head.suffix]" in mask_icon.IconStates())) ? "_[alternate_head.suffix]" : ""]")
+			standing = mutable_appearance('icons/mob/mask.dmi', "[wear_mask.icon_state][(alternate_head && ("[wear_mask.icon_state]_[alternate_head.suffix]" in mask_icon.IconStates())) ? "_[alternate_head.suffix]" : ""]", layer = FACEMASK_LAYER)
 
 		if(!istype(wear_mask, /obj/item/clothing/mask/cigarette) && wear_mask.blood_DNA)
 			var/image/bloodsies = image("icon" = dna.species.blood_mask, "icon_state" = "maskblood")
 			bloodsies.color = wear_mask.blood_color
 			standing.overlays += bloodsies
-		overlays_standing[FACEMASK_LAYER]	= standing
-	else
-		overlays_standing[FACEMASK_LAYER]	= null
-	if(update_icons)   update_icons()
+		overlays_standing[FACEMASK_LAYER] = standing
+	apply_overlay(FACEMASK_LAYER)
 
 
 /mob/living/carbon/human/update_inv_back(var/update_icons=1)
 	..()
+	remove_overlay(BACK_LAYER)
 	if(back)
 		//determine the icon to use
-		var/icon/standing
+		var/mutable_appearance/standing
 		if(back.icon_override)
-			standing = image("icon" = back.icon_override, "icon_state" = "[back.icon_state]")
+			standing = mutable_appearance(back.icon_override, "[back.icon_state]", layer = BACK_LAYER)
 		else if(istype(back, /obj/item/rig))
 			//If this is a rig and a mob_icon is set, it will take species into account in the rig update_icon() proc.
 			var/obj/item/rig/rig = back
 			standing = rig.mob_icon
 		else if(back.sprite_sheets && back.sprite_sheets[dna.species.name])
-			standing = image("icon" = back.sprite_sheets[dna.species.name], "icon_state" = "[back.icon_state]")
+			standing = mutable_appearance(back.sprite_sheets[dna.species.name], "[back.icon_state]", layer = BACK_LAYER)
 		else
-			standing = image("icon" = 'icons/mob/back.dmi', "icon_state" = "[back.icon_state]")
+			standing = mutable_appearance('icons/mob/back.dmi', "[back.icon_state]", layer = BACK_LAYER)
 
 		//create the image
 		overlays_standing[BACK_LAYER] = standing
-	else
-		overlays_standing[BACK_LAYER] = null
-
-	if(update_icons)   update_icons()
+	apply_overlay(BACK_LAYER)
 
 /mob/living/carbon/human/update_inv_handcuffed(var/update_icons=1)
-	overlays_standing[HANDCUFF_LAYER] = null
+	remove_overlay(HANDCUFF_LAYER)
 	if(handcuffed)
 		if(istype(handcuffed, /obj/item/restraints/handcuffs/pinkcuffs))
-			overlays_standing[HANDCUFF_LAYER] = image("icon" = 'icons/mob/mob.dmi', "icon_state" = "pinkcuff1")
+			overlays_standing[HANDCUFF_LAYER] = mutable_appearance('icons/mob/mob.dmi', "pinkcuff1", layer = HANDCUFF_LAYER)
 		else
-			overlays_standing[HANDCUFF_LAYER] = image("icon" = 'icons/mob/mob.dmi', "icon_state" = "handcuff1")
-
-	if(update_icons)
-		update_icons()
+			overlays_standing[HANDCUFF_LAYER] = mutable_appearance('icons/mob/mob.dmi', "handcuff1", layer = HANDCUFF_LAYER)
+	apply_overlay(HANDCUFF_LAYER)
 
 /mob/living/carbon/human/update_inv_legcuffed(var/update_icons=1)
+	remove_overlay(LEGCUFF_LAYER)
 	clear_alert("legcuffed")
 	if(legcuffed)
-		overlays_standing[LEGCUFF_LAYER]	= image("icon" = 'icons/mob/mob.dmi', "icon_state" = "legcuff1")
+		overlays_standing[LEGCUFF_LAYER] = mutable_appearance('icons/mob/mob.dmi', "legcuff1", layer = LEGCUFF_LAYER)
 		throw_alert("legcuffed", /obj/screen/alert/restrained/legcuffed, new_master = legcuffed)
 		if(m_intent != MOVE_INTENT_WALK)
 			m_intent = MOVE_INTENT_WALK
 			if(hud_used && hud_used.move_intent)
 				hud_used.move_intent.icon_state = "walking"
-
-	else
-		overlays_standing[LEGCUFF_LAYER]	= null
-	if(update_icons)
-		update_icons()
+	apply_overlay(LEGCUFF_LAYER)
 
 
 /mob/living/carbon/human/update_inv_r_hand(var/update_icons=1)
 	..()
+	remove_overlay(R_HAND_LAYER)
 	if(r_hand)
 		var/t_state = r_hand.item_state
 		if(!t_state)
 			t_state = r_hand.icon_state
 
-		var/image/I = image("icon" = r_hand.righthand_file, "icon_state" = "[t_state]")
+		var/mutable_appearance/I = mutable_appearance(r_hand.righthand_file, "[t_state]", layer = R_HAND_LAYER)
 		I = center_image(I, r_hand.inhand_x_dimension, r_hand.inhand_y_dimension)
 		overlays_standing[R_HAND_LAYER] = I
-	else
-		overlays_standing[R_HAND_LAYER] = null
-	if(update_icons)
-		update_icons()
+	apply_overlay(R_HAND_LAYER)
 
 
 /mob/living/carbon/human/update_inv_l_hand(var/update_icons=1)
 	..()
+	remove_overlay(L_HAND_LAYER)
 	if(l_hand)
 		var/t_state = l_hand.item_state
 		if(!t_state)
 			t_state = l_hand.icon_state
 
-		var/image/I = image("icon" = l_hand.lefthand_file, "icon_state" = "[t_state]")
+		var/mutable_appearance/I = mutable_appearance(l_hand.lefthand_file, "[t_state]", layer = L_HAND_LAYER)
 		I = center_image(I, l_hand.inhand_x_dimension, l_hand.inhand_y_dimension)
 		overlays_standing[L_HAND_LAYER] = I
-	else
-		overlays_standing[L_HAND_LAYER] = null
-	if(update_icons)
-		update_icons()
+	apply_overlay(L_HAND_LAYER)
 
 //human HUD updates for items in our inventory
 
@@ -1157,10 +1056,11 @@ var/global/list/damage_icon_parts = list()
 
 
 /mob/living/carbon/human/proc/update_tail_layer(var/update_icons=1)
-	overlays_standing[TAIL_UNDERLIMBS_LAYER] = null // SEW direction icons, overlayed by LIMBS_LAYER.
-	overlays_standing[TAIL_LAYER] = null /* This will be one of two things:
-											If the species' tail is overlapped by limbs, this will be only the N direction icon so tails can still appear on the outside of uniforms and such.
-											Otherwise, since the user's tail isn't overlapped by limbs, it will be a full icon with all directions. */
+	remove_overlay(TAIL_UNDERLIMBS_LAYER) // SEW direction icons, overlayed by LIMBS_LAYER.
+	remove_overlay(TAIL_LAYER) /* This will be one of two things:
+							If the species' tail is overlapped by limbs, this will be only the N direction icon so tails 
+							can still appear on the outside of uniforms and such.
+							Otherwise, since the user's tail isn't overlapped by limbs, it will be a full icon with all directions. */
 
 	var/icon/tail_marking_icon
 	var/datum/sprite_accessory/body_markings/tail/tail_marking_style
@@ -1184,16 +1084,25 @@ var/global/list/damage_icon_parts = list()
 				under.Insert(new/icon(accessory_s, dir=EAST), dir=EAST)
 				under.Insert(new/icon(accessory_s, dir=WEST), dir=WEST)
 
-				overlays_standing[TAIL_UNDERLIMBS_LAYER] = image(under, "pixel_x" = body_accessory.pixel_x_offset, "pixel_y" = body_accessory.pixel_y_offset)
+				var/mutable_appearance/underlimbs = mutable_appearance(under, layer = TAIL_UNDERLIMBS_LAYER)
+				underlimbs.pixel_x = body_accessory.pixel_x_offset
+				underlimbs.pixel_y = body_accessory.pixel_y_offset
+				overlays_standing[TAIL_UNDERLIMBS_LAYER] = underlimbs
 
 				// Creates a blank icon, and copies accessory_s' north direction sprite into it
 				// before passing that to the tail layer that overlays uniforms and such.
 				var/icon/over = new/icon("icon" = 'icons/mob/body_accessory.dmi', "icon_state" = "accessory_none_s")
 				over.Insert(new/icon(accessory_s, dir=NORTH), dir=NORTH)
 
-				overlays_standing[TAIL_LAYER] = image(over, "pixel_x" = body_accessory.pixel_x_offset, "pixel_y" = body_accessory.pixel_y_offset)
+				var/mutable_appearance/tail = mutable_appearance(over, layer = TAIL_LAYER)
+				tail.pixel_x = body_accessory.pixel_x_offset
+				tail.pixel_y = body_accessory.pixel_y_offset
+				overlays_standing[TAIL_LAYER] = tail
 			else // Otherwise, since the user's tail isn't overlapped by limbs, go ahead and use default icon generation.
-				overlays_standing[TAIL_LAYER] = image(accessory_s, "pixel_x" = body_accessory.pixel_x_offset, "pixel_y" = body_accessory.pixel_y_offset)
+				var/mutable_appearance/tail = mutable_appearance(accessory_s, layer = TAIL_LAYER)
+				tail.pixel_x = body_accessory.pixel_x_offset
+				tail.pixel_y = body_accessory.pixel_y_offset
+				overlays_standing[TAIL_LAYER] = tail
 
 	else if(tail && dna.species.bodyflags & HAS_TAIL) //no tailless tajaran
 		if(!wear_suit || !(wear_suit.flags_inv & HIDETAIL) && !istype(wear_suit, /obj/item/clothing/suit/space))
@@ -1209,25 +1118,24 @@ var/global/list/damage_icon_parts = list()
 				under.Insert(new/icon(tail_s, dir=EAST), dir=EAST)
 				under.Insert(new/icon(tail_s, dir=WEST), dir=WEST)
 
-				overlays_standing[TAIL_UNDERLIMBS_LAYER] = image(under)
+				overlays_standing[TAIL_UNDERLIMBS_LAYER] = mutable_appearance(under, layer = TAIL_UNDERLIMBS_LAYER)
 
 				// Creates a blank icon, and copies accessory_s' north direction sprite into it before passing that to the tail layer that overlays uniforms and such.
 				var/icon/over = new/icon("icon" = 'icons/effects/species.dmi', "icon_state" = "blank")
 				over.Insert(new/icon(tail_s, dir=NORTH), dir=NORTH)
 
-				overlays_standing[TAIL_LAYER] = image(over)
+				overlays_standing[TAIL_LAYER] = mutable_appearance(over, layer = TAIL_LAYER)
 			else // Otherwise, since the user's tail isn't overlapped by limbs, go ahead and use default icon generation.
-				overlays_standing[TAIL_LAYER] = image(tail_s)
-
-	if(update_icons)
-		update_icons()
-
+				overlays_standing[TAIL_LAYER] = mutable_appearance(tail_s, layer = TAIL_LAYER)
+	apply_overlay(TAIL_LAYER)
+	apply_overlay(TAIL_UNDERLIMBS_LAYER)
 
 /mob/living/carbon/human/proc/start_tail_wagging(var/update_icons=1)
-	overlays_standing[TAIL_UNDERLIMBS_LAYER] = null // SEW direction icons, overlayed by LIMBS_LAYER.
-	overlays_standing[TAIL_LAYER] = null /* This will be one of two things:
-											If the species' tail is overlapped by limbs, this will be only the N direction icon so tails can still appear on the outside of uniforms and such.
-											Otherwise, since the user's tail isn't overlapped by limbs, it will be a full icon with all directions. */
+	remove_overlay(TAIL_UNDERLIMBS_LAYER) // SEW direction icons, overlayed by LIMBS_LAYER.
+	remove_overlay(TAIL_LAYER) /* This will be one of two things:
+							If the species' tail is overlapped by limbs, this will be only the N direction icon so tails 
+							can still appear on the outside of uniforms and such.
+							Otherwise, since the user's tail isn't overlapped by limbs, it will be a full icon with all directions. */
 
 	var/icon/tail_marking_icon
 	var/datum/sprite_accessory/body_markings/tail/tail_marking_style
@@ -1252,7 +1160,10 @@ var/global/list/damage_icon_parts = list()
 			under.Insert(new/icon(accessory_s, dir=EAST), dir=EAST)
 			under.Insert(new/icon(accessory_s, dir=WEST), dir=WEST)
 
-			overlays_standing[TAIL_UNDERLIMBS_LAYER] = image(under, "pixel_x" = body_accessory.pixel_x_offset, "pixel_y" = body_accessory.pixel_y_offset)
+			var/mutable_appearance/underlimbs = mutable_appearance(under, layer = TAIL_UNDERLIMBS_LAYER)
+			underlimbs.pixel_x = body_accessory.pixel_x_offset
+			underlimbs.pixel_y = body_accessory.pixel_y_offset
+			overlays_standing[TAIL_UNDERLIMBS_LAYER] = underlimbs
 
 			// Creates a blank icon, and copies accessory_s' north direction sprite into it before passing that to the tail layer that overlays uniforms and such.
 			var/icon/over = new/icon("icon" = 'icons/effects/species.dmi', "icon_state" = "Vulpkanin_tail_delay")
@@ -1260,9 +1171,15 @@ var/global/list/damage_icon_parts = list()
 				over = new/icon("icon" = 'icons/effects/species.dmi', "icon_state" = "[dna.species.name]_tail_delay")
 			over.Insert(new/icon(accessory_s, dir=NORTH), dir=NORTH)
 
-			overlays_standing[TAIL_LAYER] = image(over, "pixel_x" = body_accessory.pixel_x_offset, "pixel_y" = body_accessory.pixel_y_offset)
+			var/mutable_appearance/tail = mutable_appearance(over, layer = TAIL_LAYER)
+			tail.pixel_x = body_accessory.pixel_x_offset
+			tail.pixel_y = body_accessory.pixel_y_offset
+			overlays_standing[TAIL_LAYER] = tail
 		else // Otherwise, since the user's tail isn't overlapped by limbs, go ahead and use default icon generation.
-			overlays_standing[TAIL_LAYER] = image(accessory_s, "pixel_x" = body_accessory.pixel_x_offset, "pixel_y" = body_accessory.pixel_y_offset)
+			var/mutable_appearance/tail = mutable_appearance(accessory_s, layer = TAIL_LAYER)
+			tail.pixel_x = body_accessory.pixel_x_offset
+			tail.pixel_y = body_accessory.pixel_y_offset
+			overlays_standing[TAIL_LAYER] = tail
 
 	else if(tail && dna.species.bodyflags & HAS_TAIL)
 		var/icon/tailw_s = new/icon("icon" = 'icons/effects/species.dmi', "icon_state" = "[tail]w_s")
@@ -1277,23 +1194,21 @@ var/global/list/damage_icon_parts = list()
 			under.Insert(new/icon(tailw_s, dir=EAST), dir=EAST)
 			under.Insert(new/icon(tailw_s, dir=WEST), dir=WEST)
 
-			overlays_standing[TAIL_UNDERLIMBS_LAYER] = image(under)
+			overlays_standing[TAIL_UNDERLIMBS_LAYER] = mutable_appearance(under, layer = TAIL_UNDERLIMBS_LAYER)
 
 			// Creates a blank icon, and copies accessory_s' north direction sprite into it before passing that to the tail layer that overlays uniforms and such.
 			var/icon/over = new/icon("icon" = 'icons/effects/species.dmi', "icon_state" = "[dna.species.name]_tail_delay")
 			over.Insert(new/icon(tailw_s, dir=NORTH), dir=NORTH)
 
-			overlays_standing[TAIL_LAYER] = image(over)
+			overlays_standing[TAIL_LAYER] = mutable_appearance(over, layer = TAIL_LAYER)
 		else // Otherwise, since the user's tail isn't overlapped by limbs, go ahead and use default icon generation.
-			overlays_standing[TAIL_LAYER] = image(tailw_s)
-
-	if(update_icons)
-		update_icons()
+			overlays_standing[TAIL_LAYER] = mutable_appearance(tailw_s, layer = TAIL_LAYER)
+	apply_overlay(TAIL_LAYER)
+	apply_overlay(TAIL_UNDERLIMBS_LAYER)
 
 /mob/living/carbon/human/proc/stop_tail_wagging(var/update_icons=1)
-	overlays_standing[TAIL_UNDERLIMBS_LAYER] = null
-	overlays_standing[TAIL_LAYER] = null
-
+	remove_overlay(TAIL_UNDERLIMBS_LAYER)
+	remove_overlay(TAIL_LAYER)
 	update_tail_layer(update_icons) //just trigger a full update for normal stationary sprites
 
 /mob/living/carbon/human/handle_transform_change()
@@ -1304,8 +1219,9 @@ var/global/list/damage_icon_parts = list()
 //	Suit needs an identically named sprite in icons/mob/collar.dmi
 //  For suits with species_fit and sprite_sheets, an identically named sprite needs to exist in a file like this icons/mob/species/[species_name_here]/collar.dmi.
 /mob/living/carbon/human/proc/update_collar(var/update_icons=1)
+	remove_overlay(COLLAR_LAYER)
 	var/icon/C = new('icons/mob/collar.dmi')
-	var/image/standing = null
+	var/mutable_appearance/standing = null
 
 	if(wear_suit)
 		if(wear_suit.icon_override)
@@ -1314,21 +1230,20 @@ var/global/list/damage_icon_parts = list()
 			if(fexists(icon_path)) //Just ensuring the nonexistance of a file with the above path won't cause a runtime.
 				var/icon/icon_file = new(icon_path)
 				if(wear_suit.icon_state in icon_file.IconStates())
-					standing = image("icon" = icon_file, "icon_state" = "[wear_suit.icon_state]")
+					standing = mutable_appearance(icon_file, "[wear_suit.icon_state]", layer = COLLAR_LAYER)
 		else if(wear_suit.sprite_sheets && wear_suit.sprite_sheets[dna.species.name])
 			var/icon_path = "[wear_suit.sprite_sheets[dna.species.name]]"
 			icon_path = "[copytext(icon_path, 1, findtext(icon_path, "/suit.dmi"))]/collar.dmi" //If this file doesn't exist, the end result is that COLLAR_LAYER will be unchanged (empty).
 			if(fexists(icon_path)) //Just ensuring the nonexistance of a file with the above path won't cause a runtime.
 				var/icon/icon_file = new(icon_path)
 				if(wear_suit.icon_state in icon_file.IconStates())
-					standing = image("icon" = icon_file, "icon_state" = "[wear_suit.icon_state]")
+					standing = mutable_appearance(icon_file, "[wear_suit.icon_state]", layer = COLLAR_LAYER)
 		else
 			if(wear_suit.icon_state in C.IconStates())
-				standing = image("icon" = C, "icon_state" = "[wear_suit.icon_state]")
+				standing = mutable_appearance(C, "[wear_suit.icon_state]", layer = COLLAR_LAYER)
 
-	overlays_standing[COLLAR_LAYER]	= standing
-
-	if(update_icons)   update_icons()
+		overlays_standing[COLLAR_LAYER]	= standing
+	apply_overlay(COLLAR_LAYER)
 
 /mob/living/carbon/human/proc/update_misc_effects()
 	misc_effect_overlays.Cut()