Cherrypicked xenophage-rewrite mechanics over.

code/game/objects/structures/alien/alien.dm

@@ -0,0 +1,66 @@
+/obj/structure/alien
+	name = "alien thing"
+	desc = "There's something alien about this."
+	icon = 'icons/mob/alien.dmi'
+	var/health = 50
+
+/obj/structure/alien/proc/healthcheck()
+	if(health <=0)
+		density = 0
+		qdel(src)
+	return
+
+/obj/structure/alien/bullet_act(var/obj/item/projectile/Proj)
+	health -= Proj.damage
+	..()
+	healthcheck()
+	return
+
+/obj/structure/alien/ex_act(severity)
+	switch(severity)
+		if(1.0)
+			health-=50
+		if(2.0)
+			health-=50
+		if(3.0)
+			if (prob(50))
+				health-=50
+			else
+				health-=25
+	healthcheck()
+	return
+
+/obj/structure/alien/blob_act()
+	health-=50
+	healthcheck()
+	return
+
+/obj/structure/alien/hitby(AM as mob|obj)
+	..()
+	visible_message("<span class='danger'>\The [src] was hit by \the [AM].</span>")
+	var/tforce = 0
+	if(ismob(AM))
+		tforce = 10
+	else
+		tforce = AM:throwforce
+	playsound(loc, 'sound/effects/attackblob.ogg', 100, 1)
+	health = max(0, health - tforce)
+	healthcheck()
+	..()
+	return
+
+/obj/structure/alien/attack_generic()
+	attack_hand(usr)
+
+/obj/structure/alien/attackby(var/obj/item/weapon/W, var/mob/user)
+	health = max(0, health - W.force)
+	playsound(loc, 'sound/effects/attackblob.ogg', 100, 1)
+	healthcheck()
+	..()
+	return
+
+/obj/structure/alien/CanPass(atom/movable/mover, turf/target, height=0, air_group=0)
+	if(air_group) return 0
+	if(istype(mover) && mover.checkpass(PASSGLASS))
+		return !opacity
+	return !density

code/game/objects/structures/alien/egg.dm

@@ -0,0 +1,80 @@
+#define MAX_PROGRESS 100
+
+/obj/structure/alien/egg
+	desc = "It looks like a weird egg."
+	name = "egg"
+	icon_state = "egg_growing"
+	density = 0
+	anchored = 1
+	var/progress = 0
+
+/obj/structure/alien/egg/New()
+	..()
+	processing_objects |= src
+
+/obj/structure/alien/egg/Destroy()
+	processing_objects -= src
+	..()
+
+/obj/structure/alien/egg/process()
+	if(progress < MAX_PROGRESS)
+		progress++
+		if(progress == MAX_PROGRESS)
+			src << "todo alert goasts"
+		update_icon()
+		return
+	// Max progress, cancel processing.
+	processing_objects -= src
+
+/obj/structure/alien/egg/update_icon()
+	if(progress == -1)
+		icon_state = "egg_hatched"
+	else if(progress < MAX_PROGRESS)
+		icon_state = "egg_growing"
+	else
+		icon_state = "egg"
+
+/obj/structure/alien/egg/attack_ghost(var/mob/dead/observer/user)
+
+	// Check for bans properly.
+	if(jobban_isbanned(user, "Xenomorph"))
+		user << "<span class='danger'>You are banned from playing a Xenomorph.</span>"
+		return
+
+	if(progress == -1) //Egg has been hatched.
+		return
+	else if(progress < MAX_PROGRESS)
+		user << "\The [src] has not yet matured."
+		return
+
+	var/confirm = alert(user, "Are you sure you want to join as a Xenomorph larva?", "Become Larva", "No", "Yes")
+
+	if(!src || confirm != "Yes")
+		return
+
+	if(!user || !user.ckey)
+		return
+
+	flick("egg_opening",src)
+	progress = -1 // No harvesting pls.
+	sleep(5)
+
+	if(!src || !user)
+		visible_message("<span class='alium'>\The [src] writhes with internal motion, but nothing comes out.</span>")
+		progress = MAX_PROGRESS // Someone else can have a go.
+		return // What a pain.
+
+	// Create the mob, transfer over key.
+	var/mob/living/carbon/alien/larva/larva = new(get_turf(src))
+	larva.ckey = user.ckey
+	spawn(-1)
+		if(user) qdel(user) // Remove the keyless ghost if it exists.
+
+	visible_message("<span class='alium'>\The [src] splits open with a wet slithering noise, and \the [larva] writhes free!</span>")
+
+	// Turn us into a hatched egg.
+	name = "hatched alien egg"
+	desc += " This one has hatched."
+	update_icon()
+
+#undef MAX_PROGRESS

code/game/objects/structures/alien/node.dm

@@ -0,0 +1,19 @@
+/obj/structure/alien/node
+	name = "alien weed node"
+	desc = "Some kind of strange, pulsating structure."
+	icon_state = "weednode"
+	health = 100
+	layer = 3.1
+
+/obj/structure/alien/node/New()
+	..()
+	processing_objects |= src
+
+/obj/structure/alien/node/Destroy()
+	processing_objects -= src
+	..()
+
+/obj/structure/alien/node/process()
+	if(locate(/obj/effect/plant) in loc)
+		return
+	new /obj/effect/plant(get_turf(src), plant_controller.seeds["xenomorph"])

code/game/objects/structures/alien/resin.dm

@@ -0,0 +1,50 @@
+/obj/structure/alien/resin
+	name = "resin"
+	desc = "Looks like some kind of slimy growth."
+	icon_state = "resin"
+
+	density = 1
+	opacity = 1
+	anchored = 1
+	health = 200
+
+/obj/structure/alien/resin/wall
+	name = "resin wall"
+	desc = "Purple slime solidified into a wall."
+	icon_state = "resinwall"
+
+/obj/structure/alien/resin/membrane
+	name = "resin membrane"
+	desc = "Purple slime just thin enough to let light pass through."
+	icon_state = "resinmembrane"
+	opacity = 0
+	health = 120
+
+/obj/structure/alien/resin/New()
+	..()
+	var/turf/T = get_turf(src)
+	T.thermal_conductivity = WALL_HEAT_TRANSFER_COEFFICIENT
+
+/obj/structure/alien/resin/Destroy()
+	var/turf/T = get_turf(src)
+	T.thermal_conductivity = initial(T.thermal_conductivity)
+	..()
+
+/obj/structure/alien/resin/attack_hand(var/mob/user)
+	if (HULK in user.mutations)
+		visible_message("<span class='danger'>\The [user] destroys \the [name]!</span>")
+		health = 0
+	else
+		// Aliens can get straight through these.
+		if(istype(user,/mob/living/carbon))
+			var/mob/living/carbon/M = user
+			if(locate(/obj/item/organ/xenos/hivenode) in M.internal_organs)
+				visible_message("<span class='alium'>\The [user] strokes \the [name] and it melts away!")
+				health = 0
+				healthcheck()
+				return
+		visible_message("<span class='danger'>\The [user] claws at \the [src]!</span>")
+		// Todo check attack datums.
+		health -= rand(5,10)
+	healthcheck()
+	return

code/game/objects/structures/lamarr_cage.dm

@@ -1,94 +0,0 @@
-/obj/structure/lamarr
-	name = "lab cage"
-	icon = 'icons/obj/stationobjs.dmi'
-	icon_state = "labcage1"
-	desc = "A glass lab container for storing interesting creatures."
-	density = 1
-	anchored = 1
-	unacidable = 1//Dissolving the case would also delete Lamarr
-	var/health = 30
-	var/occupied = 1
-	var/destroyed = 0
-
-/obj/structure/lamarr/ex_act(severity)
-	switch(severity)
-		if (1)
-			new /obj/item/weapon/material/shard( src.loc )
-			Break()
-			qdel(src)
-		if (2)
-			if (prob(50))
-				src.health -= 15
-				src.healthcheck()
-		if (3)
-			if (prob(50))
-				src.health -= 5
-				src.healthcheck()
-
-
-/obj/structure/lamarr/bullet_act(var/obj/item/projectile/Proj)
-	health -= Proj.damage
-	..()
-	src.healthcheck()
-	return
-
-
-/obj/structure/lamarr/blob_act()
-	if (prob(75))
-		new /obj/item/weapon/material/shard( src.loc )
-		Break()
-		qdel(src)
-
-/obj/structure/lamarr/proc/healthcheck()
-	if (src.health <= 0)
-		if (!( src.destroyed ))
-			src.density = 0
-			src.destroyed = 1
-			new /obj/item/weapon/material/shard( src.loc )
-			playsound(src, "shatter", 70, 1)
-			Break()
-	else
-		playsound(src.loc, 'sound/effects/Glasshit.ogg', 75, 1)
-	return
-
-/obj/structure/lamarr/update_icon()
-	if(src.destroyed)
-		src.icon_state = "labcageb[src.occupied]"
-	else
-		src.icon_state = "labcage[src.occupied]"
-	return
-
-
-/obj/structure/lamarr/attackby(obj/item/weapon/W as obj, mob/user as mob)
-	src.health -= W.force
-	src.healthcheck()
-	..()
-	return
-
-/obj/structure/lamarr/attack_hand(mob/user as mob)
-	if (src.destroyed)
-		return
-	else
-		usr << "<span class='notice'>You kick the lab cage.</span>"
-		for(var/mob/O in oviewers())
-			if ((O.client && !( O.blinded )))
-				O << "<span class='warning'>[usr] kicks the lab cage.</span>"
-		src.health -= 2
-		healthcheck()
-		return
-
-/obj/structure/lamarr/proc/Break()
-	if(occupied)
-		new /obj/item/clothing/mask/facehugger/lamarr(src.loc)
-		occupied = 0
-	update_icon()
-	return
-
-/obj/item/clothing/mask/facehugger/lamarr
-	name = "Lamarr"
-	desc = "The worst she might do is attempt to... couple with your head."//hope we don't get sued over a harmless reference, rite?
-	sterile = 1
-	gender = FEMALE
-
-/obj/item/clothing/mask/facehugger/lamarr/New()//to prevent deleting it if aliums are disabled
-	return