Converts Lizards to Basic Mobs (#75515)

This was pretty simple since they didn't have too much custom behavior,
and whatever they did have already had AI behavior. I got really burned
out the last two times I wrote intricate AI action/decision behaviors so
I'm just taking it light and doing the bare minimum.

one day our shackles will be free of the simple animal scourge. they're
also a bit more intelligent, and i daresay a bit cuter too now.

also that lizard gib animation has been sitting there for god knows how
long completely unseen, so let's actually hook it into the mob.

code/modules/mob/living/basic/vermin/lizard.dm

@@ -0,0 +1,85 @@
+/*
+* ## Lizards
+*
+* Green things that crawl around and eat bugs. Not to be confused with the human species lizardpersons, these are just small little fellas.
+*/
+
+/mob/living/basic/lizard
+	name = "Lizard"
+	desc = "A cute tiny lizard."
+	icon_state = "lizard"
+	icon_living = "lizard"
+	icon_dead = "lizard_dead"
+	icon_gib = "lizard_gib"
+	speak_emote = list("hisses")
+	health = 10
+	maxHealth = 10
+	faction = list(FACTION_LIZARD)
+	attack_verb_continuous = "bites"
+	attack_verb_simple = "bite"
+	melee_damage_lower = 1
+	melee_damage_upper = 2
+	response_help_continuous = "pets"
+	response_help_simple = "pet"
+	response_disarm_continuous = "shoos"
+	response_disarm_simple = "shoo"
+	response_harm_continuous = "stomps on"
+	response_harm_simple = "stomp on"
+	density = FALSE
+	pass_flags = PASSTABLE | PASSMOB
+	mob_size = MOB_SIZE_SMALL
+	mob_biotypes = MOB_ORGANIC|MOB_BEAST|MOB_REPTILE
+	gold_core_spawnable = FRIENDLY_SPAWN
+	obj_damage = 0
+	environment_smash = ENVIRONMENT_SMASH_NONE
+	can_be_held = TRUE
+	ai_controller = /datum/ai_controller/basic_controller/lizard
+
+	/// Typecache of things that we seek out to eat. Yummy.
+	var/static/list/edibles = typecacheof(list(
+		/mob/living/basic/cockroach,
+		/mob/living/simple_animal/butterfly,
+	))
+
+/mob/living/basic/lizard/Initialize(mapload)
+	. = ..()
+	ADD_TRAIT(src, TRAIT_VENTCRAWLER_ALWAYS, INNATE_TRAIT)
+	AddElement(/datum/element/pet_bonus, "sticks its tongue out contentedly!")
+	AddElement(/datum/element/basic_eating, 5, 0, null, edibles)
+	ai_controller.set_blackboard_key(BB_BASIC_FOODS, edibles)
+
+/datum/ai_controller/basic_controller/lizard
+	blackboard = list(
+		BB_TARGETTING_DATUM = new /datum/targetting_datum/basic/allow_items(),
+	)
+
+	ai_traits = STOP_MOVING_WHEN_PULLED
+	ai_movement = /datum/ai_movement/basic_avoidance
+	idle_behavior = /datum/idle_behavior/idle_random_walk
+	planning_subtrees = list(
+		/datum/ai_planning_subtree/find_food,
+		/datum/ai_planning_subtree/basic_melee_attack_subtree,
+		/datum/ai_planning_subtree/random_speech/lizard,
+	)
+
+//Subtypes of lizards follow.
+
+/// Lizards that can survive in space.
+/mob/living/basic/lizard/space
+	name = "Space Lizard"
+	desc = "A cute tiny lizard with a tiny space helmet."
+	icon_state = "lizard_space"
+	icon_living = "lizard_space"
+	unsuitable_atmos_damage = 0
+	minimum_survivable_temperature = TCMB
+	maximum_survivable_temperature = T0C + 40
+
+/// Janitor's pet lizard.
+/mob/living/basic/lizard/wags_his_tail
+	name = "Wags-His-Tail"
+	desc = "The janitorial department's trusty pet lizard."
+
+/// Another pet lizard for the janitor.
+/mob/living/basic/lizard/eats_the_roaches
+	name = "Eats-The-Roaches"
+	desc = "The janitorial department's less trusty pet lizard."