Datumizes DNA blocks, makes DNA cleaner in general (#92061)

## About The Pull Request

Moves all the dna block handling onto singleton datums initialized
inside global lists, to make the handling dna less of a copy-paste mess
and make adding new blocks significantly easier. There is still some
work to be done in the copypaste department but ultimately that falls
under its own PR scope after the core refactor goes through. (Ill
probably do those but it will also be easier for everyone else as the
code is now significantly less of an eyesore)

Both features and identities have been tested through and through, and
seem to be working fine.

Also removed the reliance on weird hardcoded lookup tables for length,
and other similar things that just didn't make sense when I was passing
through DNA code. There's a lot more that fall out of scope for this
exact PR's goal however

## Why It's Good For The Game

I've been told the maintainers will love me for doing this

## Changelog

🆑
code: feature keys are no longer magical strings floating around the
codebase and use proper defines
refactor: DNA blocks are now handled with singleton datums.
/🆑

code/__DEFINES/DNA.dm

@@ -44,55 +44,40 @@
 
 //DNA - Because fuck you and your magic numbers being all over the codebase.
 #define DNA_BLOCK_SIZE 3
-
 #define DNA_BLOCK_SIZE_COLOR DEFAULT_HEX_COLOR_LEN
 
-#define DNA_GENDER_BLOCK 1
-#define DNA_SKIN_TONE_BLOCK 2
-#define DNA_EYE_COLOR_LEFT_BLOCK 3
-#define DNA_EYE_COLOR_RIGHT_BLOCK 4
-#define DNA_HAIRSTYLE_BLOCK 5
-#define DNA_HAIR_COLOR_BLOCK 6
-#define DNA_FACIAL_HAIRSTYLE_BLOCK 7
-#define DNA_FACIAL_HAIR_COLOR_BLOCK 8
-#define DNA_HAIRSTYLE_GRADIENT_BLOCK 9
-#define DNA_HAIR_COLOR_GRADIENT_BLOCK 10
-#define DNA_FACIAL_HAIRSTYLE_GRADIENT_BLOCK 11
-#define DNA_FACIAL_HAIR_COLOR_GRADIENT_BLOCK 12
-
-#define DNA_UNI_IDENTITY_BLOCKS 12
-
-/// This number needs to equal the total number of DNA blocks
-#define DNA_MUTANT_COLOR_BLOCK 1
-#define DNA_ETHEREAL_COLOR_BLOCK 2
-#define DNA_LIZARD_MARKINGS_BLOCK 3
-#define DNA_TAIL_BLOCK 4
-#define DNA_LIZARD_TAIL_BLOCK 5
-#define DNA_SNOUT_BLOCK 6
-#define DNA_HORNS_BLOCK 7
-#define DNA_FRILLS_BLOCK 8
-#define DNA_SPINES_BLOCK 9
-#define DNA_EARS_BLOCK 10
-#define DNA_MOTH_WINGS_BLOCK 11
-#define DNA_MOTH_ANTENNAE_BLOCK 12
-#define DNA_MOTH_MARKINGS_BLOCK 13
-#define DNA_MUSHROOM_CAPS_BLOCK 14
-#define DNA_POD_HAIR_BLOCK 15
-#define DNA_FISH_TAIL_BLOCK 16
-
-// Hey! Listen up if you're here because you're adding a species feature!
-//
-// You don't need to add a DNA block for EVERY species feature!
-// You ONLY need DNA blocks if you intend to allow players to change it via GENETICS!
-// (Which means having a DNA block for a feature tied to a mob without DNA is entirely pointless.)
-
-/// Total amount of DNA blocks, must be equal to the highest DNA block number
-#define DNA_FEATURE_BLOCKS 16
-
 #define DNA_SEQUENCE_LENGTH 4
 #define DNA_MUTATION_BLOCKS 8
 #define DNA_UNIQUE_ENZYMES_LEN 32
 
+//Features - No more magic strings
+//These can't just simply use dna block paths like identities, because there's keys that aren't tied to blocks
+
+// Block tied
+#define FEATURE_MUTANT_COLOR "mcolor"
+#define FEATURE_ETHEREAL_COLOR "ethcolor"
+#define FEATURE_EARS "ears"
+#define FEATURE_TAIL "tail_cat"
+#define FEATURE_TAIL_LIZARD "tail_lizard"
+#define FEATURE_TAIL_FISH "tail_fish"
+#define FEATURE_SNOUT "snout"
+#define FEATURE_LIZARD_MARKINGS "marking_lizard"
+#define FEATURE_HORNS "horns"
+#define FEATURE_FRILLS "frills"
+#define FEATURE_SPINES "spines"
+#define FEATURE_MOTH_WINGS "moth_wings"
+#define FEATURE_MOTH_ANTENNAE "moth_antennae"
+#define FEATURE_MOTH_MARKINGS "moth_markings"
+#define FEATURE_MUSH_CAP "caps"
+#define FEATURE_POD_HAIR "pod_hair"
+
+// Other
+#define FEATURE_WINGS "wings"
+#define FEATURE_TAIL_MONKEY "tail_monkey"
+#define FEATURE_TAIL_XENO "tail_xeno"
+#define FEATURE_TAILSPINES "tailspines" // Different from regular spines, these appear on tails
+#define FEATURE_LEGS "legs"
+
 ///flag for the transfer_flag argument from dna/proc/copy_dna(). This one makes it so the SE is copied too.
 #define COPY_DNA_SE (1<<0)
 ///flag for the transfer_flag argument from dna/proc/copy_dna(). This one copies the species.

code/__HELPERS/dna.dm

@@ -12,7 +12,5 @@
 #define GET_MUTATION_POWER(A) ((A.power_coeff < 0) ? 1 : A.power_coeff)
 #define GET_MUTATION_ENERGY(A) ((A.energy_coeff < 0) ? 1 : A.energy_coeff)
 
-///Getter macro used to get the length of a identity block
-#define GET_UI_BLOCK_LEN(blocknum) (GLOB.identity_block_lengths["[blocknum]"] || DNA_BLOCK_SIZE)
 ///Ditto, but for a feature.
 #define GET_UF_BLOCK_LEN(blocknum) (GLOB.features_block_lengths["[blocknum]"] || DNA_BLOCK_SIZE)

code/_globalvars/lists/mobs.dm

@@ -197,3 +197,21 @@ GLOBAL_LIST_INIT(construct_radial_images, list(
 		if(mind)
 			minds += mind
 	return minds
+
+/// A keyed list of identity block singletons, in a key:value group of typepath:block
+GLOBAL_LIST_INIT(dna_identity_blocks, init_identity_block_types())
+
+/proc/init_identity_block_types()
+	. = list()
+	for(var/datum/dna_block/identity/block_path as anything in subtypesof(/datum/dna_block/identity))
+		var/datum/dna_block/identity/new_block = new block_path()
+		.[block_path] = new_block
+
+/// A keyed list of feature block singletons, in a key:value group of typepath:block
+GLOBAL_LIST_INIT(dna_feature_blocks, init_feature_block_types())
+
+/proc/init_feature_block_types()
+	. = list()
+	for(var/datum/dna_block/feature/block_path as anything in subtypesof(/datum/dna_block/feature))
+		var/datum/dna_block/feature/new_block = new block_path()
+		.[block_path] = new_block

code/controllers/subsystem/sprite_accessories.dm

@@ -11,6 +11,7 @@ SUBSYSTEM_DEF(accessories) // just 'accessories' for brevity
 	name = "Sprite Accessories"
 	flags = SS_NO_FIRE | SS_NO_INIT
 
+	// HOLY SHIT COMPACT THIS INTO ASSOCIATED LISTS SO WE STOP ADDING VARIABLES
 	//Hairstyles
 	var/list/hairstyles_list //! stores /datum/sprite_accessory/hair indexed by name
 	var/list/hairstyles_male_list //! stores only hair names

code/datums/bodypart_overlays/markings_bodypart_overlay.dm

@@ -43,13 +43,13 @@
 	return mutable_appearance(icon, gender_string + icon_state + "_" + limb.body_zone, layer = layer)
 
 /datum/bodypart_overlay/simple/body_marking/moth
-	dna_feature_key = "moth_markings"
+	dna_feature_key = FEATURE_MOTH_MARKINGS
 
 /datum/bodypart_overlay/simple/body_marking/moth/get_accessory(name)
 	return SSaccessories.moth_markings_list[name]
 
 /datum/bodypart_overlay/simple/body_marking/lizard
-	dna_feature_key = "lizard_markings"
+	dna_feature_key = FEATURE_LIZARD_MARKINGS
 	applies_to = list(/obj/item/bodypart/chest)
 
 /datum/bodypart_overlay/simple/body_marking/lizard/get_accessory(name)

code/datums/dna/blocks/dna_features_block.dm

@@ -0,0 +1,151 @@
+/datum/dna_block/feature/mutant_color
+	block_length = DNA_BLOCK_SIZE_COLOR
+	feature_key = FEATURE_MUTANT_COLOR
+
+/datum/dna_block/feature/mutant_color/create_unique_block(mob/living/carbon/human/target)
+	return sanitize_hexcolor(target.dna.features[feature_key], include_crunch = FALSE)
+
+/datum/dna_block/feature/mutant_color/apply_to_mob(mob/living/carbon/human/target, dna_hash)
+	target.dna.features[feature_key] = sanitize_hexcolor(get_block(dna_hash))
+
+/datum/dna_block/feature/ethereal_color
+	block_length = DNA_BLOCK_SIZE_COLOR
+	feature_key = FEATURE_ETHEREAL_COLOR
+
+/datum/dna_block/feature/ethereal_color/create_unique_block(mob/living/carbon/human/target)
+	return sanitize_hexcolor(target.dna.features[FEATURE_ETHEREAL_COLOR], include_crunch = FALSE)
+
+/datum/dna_block/feature/ethereal_color/apply_to_mob(mob/living/carbon/human/target, dna_hash)
+	target.dna.features[feature_key] = sanitize_hexcolor(get_block(dna_hash))
+
+/datum/dna_block/feature/ears
+	feature_key = FEATURE_EARS
+
+/datum/dna_block/feature/ears/create_unique_block(mob/living/carbon/human/target)
+	return construct_block(SSaccessories.ears_list.Find(target.dna.features[feature_key]), length(SSaccessories.ears_list))
+
+/datum/dna_block/feature/ears/apply_to_mob(mob/living/carbon/human/target, dna_hash)
+	target.dna.features[feature_key] = SSaccessories.ears_list[deconstruct_block(get_block(dna_hash), length(SSaccessories.ears_list))]
+
+// One day, someone should consider merging all tails into one, this is stupid
+// No I don't care that it will "Create situations where a felinid grows a lizard tail" that makes it more fun
+/datum/dna_block/feature/tail
+	feature_key = FEATURE_TAIL
+
+/datum/dna_block/feature/tail/create_unique_block(mob/living/carbon/human/target)
+	return construct_block(SSaccessories.tails_list_felinid.Find(target.dna.features[feature_key]), length(SSaccessories.tails_list_felinid))
+
+/datum/dna_block/feature/tail/apply_to_mob(mob/living/carbon/human/target, dna_hash)
+	target.dna.features[feature_key] = SSaccessories.tails_list_felinid[deconstruct_block(get_block(dna_hash), length(SSaccessories.tails_list_felinid))]
+
+/datum/dna_block/feature/tail_lizard
+	feature_key = FEATURE_TAIL_LIZARD
+
+/datum/dna_block/feature/tail_lizard/create_unique_block(mob/living/carbon/human/target)
+	return construct_block(SSaccessories.tails_list_lizard.Find(target.dna.features[feature_key]), length(SSaccessories.tails_list_lizard))
+
+/datum/dna_block/feature/tail_lizard/apply_to_mob(mob/living/carbon/human/target, dna_hash)
+	target.dna.features[feature_key] = SSaccessories.tails_list_lizard[deconstruct_block(get_block(dna_hash), length(SSaccessories.tails_list_lizard))]
+
+/datum/dna_block/feature/tail_fish
+	feature_key = FEATURE_TAIL_FISH
+
+/datum/dna_block/feature/tail_fish/create_unique_block(mob/living/carbon/human/target)
+	return construct_block(SSaccessories.tails_list_fish.Find(target.dna.features[feature_key]), length(SSaccessories.tails_list_fish))
+
+/datum/dna_block/feature/tail_fish/apply_to_mob(mob/living/carbon/human/target, dna_hash)
+	target.dna.features[feature_key] = SSaccessories.tails_list_fish[deconstruct_block(get_block(dna_hash), length(SSaccessories.tails_list_fish))]
+
+/datum/dna_block/feature/snout
+	feature_key = FEATURE_SNOUT
+
+/datum/dna_block/feature/snout/create_unique_block(mob/living/carbon/human/target)
+	return construct_block(SSaccessories.snouts_list.Find(target.dna.features[feature_key]), length(SSaccessories.snouts_list))
+
+/datum/dna_block/feature/snout/apply_to_mob(mob/living/carbon/human/target, dna_hash)
+	target.dna.features[feature_key] = SSaccessories.snouts_list[deconstruct_block(get_block(dna_hash), length(SSaccessories.snouts_list))]
+
+/datum/dna_block/feature/lizard_marking
+	feature_key = FEATURE_LIZARD_MARKINGS
+
+/datum/dna_block/feature/lizard_marking/create_unique_block(mob/living/carbon/human/target)
+	return construct_block(SSaccessories.lizard_markings_list.Find(target.dna.features[feature_key]), length(SSaccessories.lizard_markings_list))
+
+/datum/dna_block/feature/lizard_marking/apply_to_mob(mob/living/carbon/human/target, dna_hash)
+	target.dna.features[feature_key] = SSaccessories.lizard_markings_list[deconstruct_block(get_block(dna_hash), length(SSaccessories.lizard_markings_list))]
+
+/datum/dna_block/feature/horn
+	feature_key = FEATURE_HORNS
+
+/datum/dna_block/feature/horn/create_unique_block(mob/living/carbon/human/target)
+	return construct_block(SSaccessories.horns_list.Find(target.dna.features[feature_key]), length(SSaccessories.horns_list))
+
+/datum/dna_block/feature/horn/apply_to_mob(mob/living/carbon/human/target, dna_hash)
+	target.dna.features[feature_key] = SSaccessories.horns_list[deconstruct_block(get_block(dna_hash), length(SSaccessories.horns_list))]
+
+/datum/dna_block/feature/frill
+	feature_key = FEATURE_FRILLS
+
+/datum/dna_block/feature/frill/create_unique_block(mob/living/carbon/human/target)
+	return construct_block(SSaccessories.frills_list.Find(target.dna.features[feature_key]), length(SSaccessories.frills_list))
+
+/datum/dna_block/feature/frill/apply_to_mob(mob/living/carbon/human/target, dna_hash)
+	target.dna.features[feature_key] = SSaccessories.frills_list[deconstruct_block(get_block(dna_hash), length(SSaccessories.frills_list))]
+
+/datum/dna_block/feature/spine
+	feature_key = FEATURE_SPINES
+
+/datum/dna_block/feature/spine/create_unique_block(mob/living/carbon/human/target)
+	return construct_block(SSaccessories.spines_list.Find(target.dna.features[feature_key]), length(SSaccessories.spines_list))
+
+/datum/dna_block/feature/spine/apply_to_mob(mob/living/carbon/human/target, dna_hash)
+	target.dna.features[feature_key] = SSaccessories.spines_list[deconstruct_block(get_block(dna_hash), length(SSaccessories.spines_list))]
+
+/datum/dna_block/feature/moth_wing
+	feature_key = FEATURE_MOTH_WINGS
+
+/datum/dna_block/feature/moth_wing/create_unique_block(mob/living/carbon/human/target)
+	if(target.dna.features[feature_key] == "Burnt Off") // Why is this snowflake check a thing. Please find a way to fix this later
+		return random_string(block_length, GLOB.hex_characters)
+	return construct_block(SSaccessories.moth_wings_list.Find(target.dna.features[feature_key]), length(SSaccessories.moth_wings_list))
+
+/datum/dna_block/feature/moth_wing/apply_to_mob(mob/living/carbon/human/target, dna_hash)
+	target.dna.features[feature_key] = SSaccessories.moth_wings_list[deconstruct_block(get_block(dna_hash), length(SSaccessories.moth_wings_list))]
+
+/datum/dna_block/feature/moth_antenna
+	feature_key = FEATURE_MOTH_ANTENNAE
+
+/datum/dna_block/feature/moth_antenna/create_unique_block(mob/living/carbon/human/target)
+	if(target.dna.features[feature_key] == "Burnt Off")
+		return random_string(block_length, GLOB.hex_characters)
+	return construct_block(SSaccessories.moth_antennae_list.Find(target.dna.features[feature_key]), length(SSaccessories.moth_antennae_list))
+
+/datum/dna_block/feature/moth_antenna/apply_to_mob(mob/living/carbon/human/target, dna_hash)
+	target.dna.features[feature_key] = SSaccessories.moth_antennae_list[deconstruct_block(get_block(dna_hash), length(SSaccessories.moth_antennae_list))]
+
+/datum/dna_block/feature/moth_marking
+	feature_key = FEATURE_MOTH_MARKINGS
+
+/datum/dna_block/feature/moth_marking/create_unique_block(mob/living/carbon/human/target)
+	return construct_block(SSaccessories.moth_markings_list.Find(target.dna.features[feature_key]), length(SSaccessories.moth_markings_list))
+
+/datum/dna_block/feature/moth_marking/apply_to_mob(mob/living/carbon/human/target, dna_hash)
+	target.dna.features[feature_key] = SSaccessories.moth_markings_list[deconstruct_block(get_block(dna_hash), length(SSaccessories.moth_markings_list))]
+
+/datum/dna_block/feature/mush_cap
+	feature_key = FEATURE_MUSH_CAP
+
+/datum/dna_block/feature/mush_cap/create_unique_block(mob/living/carbon/human/target)
+	return construct_block(SSaccessories.caps_list.Find(target.dna.features[feature_key]), length(SSaccessories.caps_list))
+
+/datum/dna_block/feature/mush_cap/apply_to_mob(mob/living/carbon/human/target, dna_hash)
+	target.dna.features[feature_key] = SSaccessories.caps_list[deconstruct_block(get_block(dna_hash), length(SSaccessories.caps_list))]
+
+/datum/dna_block/feature/pod_hair
+	feature_key = FEATURE_POD_HAIR
+
+/datum/dna_block/feature/pod_hair/create_unique_block(mob/living/carbon/human/target)
+	return construct_block(SSaccessories.pod_hair_list.Find(target.dna.features[feature_key]), length(SSaccessories.pod_hair_list))
+
+/datum/dna_block/feature/pod_hair/apply_to_mob(mob/living/carbon/human/target, dna_hash)
+	target.dna.features[feature_key] = SSaccessories.pod_hair_list[deconstruct_block(get_block(dna_hash), length(SSaccessories.pod_hair_list))]

code/datums/dna/blocks/dna_identity_block.dm

@@ -0,0 +1,129 @@
+/datum/dna_block/identity/gender
+
+/datum/dna_block/identity/gender/create_unique_block(mob/living/carbon/human/target)
+	//ignores TRAIT_AGENDER so that a "real" gender can be stored in the DNA if later use is needed
+	switch(target.gender)
+		if(MALE)
+			. = construct_block(G_MALE, GENDERS)
+		if(FEMALE)
+			. = construct_block(G_FEMALE, GENDERS)
+		if(NEUTER)
+			. = construct_block(G_NEUTER, GENDERS)
+		else
+			. = construct_block(G_PLURAL, GENDERS)
+	return .
+
+/datum/dna_block/identity/gender/apply_to_mob(mob/living/carbon/human/target, dna_hash)
+	//Always plural gender if agender
+	if(HAS_TRAIT(target, TRAIT_AGENDER))
+		target.gender = PLURAL
+		return
+	switch(deconstruct_block(get_block(dna_hash), GENDERS))
+		if(G_MALE)
+			target.gender = MALE
+		if(G_FEMALE)
+			target.gender = FEMALE
+		if(G_NEUTER)
+			target.gender = NEUTER
+		else
+			target.gender = PLURAL
+
+/datum/dna_block/identity/skin_tone
+
+/datum/dna_block/identity/skin_tone/create_unique_block(mob/living/carbon/human/target)
+	return construct_block(GLOB.skin_tones.Find(target.skin_tone), GLOB.skin_tones.len)
+
+/datum/dna_block/identity/skin_tone/apply_to_mob(mob/living/carbon/human/target, dna_hash)
+	target.skin_tone = GLOB.skin_tones[deconstruct_block(get_block(dna_hash), GLOB.skin_tones.len)]
+
+/// Holds both the left and right eye color at once
+/datum/dna_block/identity/eye_colors
+	block_length = DNA_BLOCK_SIZE_COLOR * 2 // Left eye color, then right eye color
+
+/datum/dna_block/identity/eye_colors/create_unique_block(mob/living/carbon/human/target)
+	var/left = sanitize_hexcolor(target.eye_color_left, include_crunch = FALSE)
+	var/right = sanitize_hexcolor(target.eye_color_right, include_crunch = FALSE)
+	return left + right
+
+/datum/dna_block/identity/eye_colors/apply_to_mob(mob/living/carbon/human/target, dna_hash)
+	var/colors = get_block(dna_hash)
+	var/right_color_begin = DNA_BLOCK_SIZE_COLOR + 1
+	target.set_eye_color(sanitize_hexcolor(copytext(colors, 1, right_color_begin)), sanitize_hexcolor(copytext(colors, right_color_begin, length(colors) + 1)))
+
+/datum/dna_block/identity/hair_style
+
+/datum/dna_block/identity/hair_style/create_unique_block(mob/living/carbon/human/target)
+	return construct_block(SSaccessories.hairstyles_list.Find(target.hairstyle), length(SSaccessories.hairstyles_list))
+
+/datum/dna_block/identity/hair_style/apply_to_mob(mob/living/carbon/human/target, dna_hash)
+	if(HAS_TRAIT(target, TRAIT_BALD))
+		target.set_hairstyle("Bald", update = FALSE)
+		return
+	var/style = SSaccessories.hairstyles_list[deconstruct_block(get_block(dna_hash), length(SSaccessories.hairstyles_list))]
+	target.set_hairstyle(style, update = FALSE)
+
+/datum/dna_block/identity/hair_color
+	block_length = DNA_BLOCK_SIZE_COLOR
+
+/datum/dna_block/identity/hair_color/create_unique_block(mob/living/carbon/human/target)
+	return sanitize_hexcolor(target.hair_color, include_crunch = FALSE)
+
+/datum/dna_block/identity/hair_color/apply_to_mob(mob/living/carbon/human/target, dna_hash)
+	target.set_haircolor(sanitize_hexcolor(get_block(dna_hash)), update = FALSE)
+
+/datum/dna_block/identity/facial_style
+
+/datum/dna_block/identity/facial_style/create_unique_block(mob/living/carbon/human/target)
+	return construct_block(SSaccessories.facial_hairstyles_list.Find(target.facial_hairstyle), length(SSaccessories.facial_hairstyles_list))
+
+/datum/dna_block/identity/facial_style/apply_to_mob(mob/living/carbon/human/target, dna_hash)
+	if(HAS_TRAIT(src, TRAIT_SHAVED))
+		target.set_facial_hairstyle("Shaved", update = FALSE)
+		return
+	var/style = SSaccessories.facial_hairstyles_list[deconstruct_block(get_block(dna_hash), length(SSaccessories.facial_hairstyles_list))]
+	target.set_facial_hairstyle(style, update = FALSE)
+
+/datum/dna_block/identity/facial_color
+	block_length = DNA_BLOCK_SIZE_COLOR
+
+/datum/dna_block/identity/facial_color/create_unique_block(mob/living/carbon/human/target)
+	return sanitize_hexcolor(target.facial_hair_color, include_crunch = FALSE)
+
+/datum/dna_block/identity/facial_color/apply_to_mob(mob/living/carbon/human/target, dna_hash)
+	target.set_facial_haircolor(sanitize_hexcolor(get_block(dna_hash)), update = FALSE)
+
+/datum/dna_block/identity/hair_gradient
+
+/datum/dna_block/identity/hair_gradient/create_unique_block(mob/living/carbon/human/target)
+	return construct_block(SSaccessories.hair_gradients_list.Find(target.grad_style[GRADIENT_HAIR_KEY]), length(SSaccessories.hair_gradients_list))
+
+/datum/dna_block/identity/hair_gradient/apply_to_mob(mob/living/carbon/human/target, dna_hash)
+	var/gradient_style = SSaccessories.hair_gradients_list[deconstruct_block(get_block(dna_hash), length(SSaccessories.hair_gradients_list))]
+	target.set_hair_gradient_style(gradient_style, update = FALSE)
+
+/datum/dna_block/identity/hair_gradient_color
+	block_length = DNA_BLOCK_SIZE_COLOR
+
+/datum/dna_block/identity/hair_gradient_color/create_unique_block(mob/living/carbon/human/target)
+	return sanitize_hexcolor(target.grad_color[GRADIENT_HAIR_KEY], include_crunch = FALSE)
+
+/datum/dna_block/identity/hair_gradient_color/apply_to_mob(mob/living/carbon/human/target, dna_hash)
+	target.set_hair_gradient_color(sanitize_hexcolor(get_block(dna_hash)), update = FALSE)
+
+/datum/dna_block/identity/facial_gradient
+
+/datum/dna_block/identity/facial_gradient/create_unique_block(mob/living/carbon/human/target)
+	return construct_block(SSaccessories.facial_hair_gradients_list.Find(target.grad_style[GRADIENT_FACIAL_HAIR_KEY]), length(SSaccessories.facial_hair_gradients_list))
+
+/datum/dna_block/identity/facial_gradient/apply_to_mob(mob/living/carbon/human/target, dna_hash)
+	var/gradient_style = SSaccessories.hair_gradients_list[deconstruct_block(get_block(dna_hash), length(SSaccessories.hair_gradients_list))]
+	target.set_facial_hair_gradient_style(gradient_style, update = FALSE)
+
+/datum/dna_block/identity/facial_gradient_color
+	block_length = DNA_BLOCK_SIZE_COLOR
+
+/datum/dna_block/identity/facial_gradient_color/create_unique_block(mob/living/carbon/human/target)
+	return sanitize_hexcolor(target.grad_color[GRADIENT_FACIAL_HAIR_KEY], include_crunch = FALSE)
+
+/datum/dna_block/identity/facial_gradient_color/apply_to_mob(mob/living/carbon/human/target, dna_hash)
+	target.set_facial_hair_gradient_color(sanitize_hexcolor(get_block(dna_hash)), update = FALSE)

code/datums/dna/dna.dm

@@ -1,31 +1,3 @@
-
-/**
- * Some identity blocks (basically pieces of the unique_identity string variable of the dna datum, commonly abbreviated with ui)
- * may have a length that differ from standard length of 3 ASCII characters. This list is necessary
- * for these non-standard blocks to work, as well as the entire unique identity string.
- * Should you add a new ui block which size differ from the standard (again, 3 ASCII characters), like for example, a color,
- * please do not forget to also include it in this list in the following format:
- *  "[dna block number]" = dna block size,
- * Failure to do that may result in bugs. Thanks.
- */
-GLOBAL_LIST_INIT(identity_block_lengths, list(
-		"[DNA_HAIR_COLOR_BLOCK]" = DNA_BLOCK_SIZE_COLOR,
-		"[DNA_FACIAL_HAIR_COLOR_BLOCK]" = DNA_BLOCK_SIZE_COLOR,
-		"[DNA_EYE_COLOR_LEFT_BLOCK]" = DNA_BLOCK_SIZE_COLOR,
-		"[DNA_EYE_COLOR_RIGHT_BLOCK]" = DNA_BLOCK_SIZE_COLOR,
-		"[DNA_HAIR_COLOR_GRADIENT_BLOCK]" = DNA_BLOCK_SIZE_COLOR,
-		"[DNA_FACIAL_HAIR_COLOR_GRADIENT_BLOCK]" = DNA_BLOCK_SIZE_COLOR,
-	))
-
-/**
- * The same rules of the above also apply here, with the exception that this is for the unique_features string variable
- * (commonly abbreviated with uf) and its blocks. Both ui and uf have a standard block length of 3 ASCII characters.
- */
-GLOBAL_LIST_INIT(features_block_lengths, list(
-		"[DNA_MUTANT_COLOR_BLOCK]" = DNA_BLOCK_SIZE_COLOR,
-		"[DNA_ETHEREAL_COLOR_BLOCK]" = DNA_BLOCK_SIZE_COLOR,
-	))
-
 /**
  * A list of numbers that keeps track of where ui blocks start in the unique_identity string variable of the dna datum.
  * Commonly used by the datum/dna/set_uni_identity_block and datum/dna/get_uni_identity_block procs.
@@ -37,9 +9,10 @@ GLOBAL_LIST_INIT(standard_mutation_sources, list(MUTATION_SOURCE_ACTIVATED, MUTA
 /proc/populate_total_ui_len_by_block()
 	. = list()
 	var/total_block_len = 1
-	for(var/blocknumber in 1 to DNA_UNI_IDENTITY_BLOCKS)
+	for(var/block_path in GLOB.dna_identity_blocks)
-		. += total_block_len
+		var/datum/dna_block/identity/block = GLOB.dna_identity_blocks[block_path]
-		total_block_len += GET_UI_BLOCK_LEN(blocknumber)
+		.[block_path] += total_block_len
+		total_block_len += block.block_length
 
 ///Ditto but for unique features. Used by the datum/dna/set_uni_feature_block and datum/dna/get_uni_feature_block procs.
 GLOBAL_LIST_INIT(total_uf_len_by_block, populate_total_uf_len_by_block())
@@ -47,9 +20,10 @@ GLOBAL_LIST_INIT(total_uf_len_by_block, populate_total_uf_len_by_block())
 /proc/populate_total_uf_len_by_block()
 	. = list()
 	var/total_block_len = 1
-	for(var/blocknumber in 1 to DNA_FEATURE_BLOCKS)
+	for(var/block_path in GLOB.dna_feature_blocks)
-		. += total_block_len
+		var/datum/dna_block/feature/block = GLOB.dna_feature_blocks[block_path]
-		total_block_len += GET_UF_BLOCK_LEN(blocknumber)
+		.[block_path] += total_block_len
+		total_block_len += block.block_length
 
 /////////////////////////// DNA DATUM
 /datum/dna
@@ -63,7 +37,7 @@ GLOBAL_LIST_INIT(total_uf_len_by_block, populate_total_uf_len_by_block())
 	var/datum/species/species = new /datum/species/human
 	/// Assoc list of feature keys to their value
 	/// Note if you set these manually, and do not update [unique_features] afterwards, it will likely be reset.
-	var/list/features = list("mcolor" = COLOR_WHITE)
+	var/list/features = list(FEATURE_MUTANT_COLOR = COLOR_WHITE)
 	///Stores the hashed values of the person's non-human features
 	var/unique_features
 	///Stores the real name of the person who originally got this dna datum. Used primarily for changelings
@@ -211,77 +185,18 @@ GLOBAL_LIST_INIT(total_uf_len_by_block, populate_total_uf_len_by_block())
 
 /datum/dna/proc/generate_unique_identity()
 	. = ""
-	var/list/L = new /list(DNA_UNI_IDENTITY_BLOCKS)
+	for(var/block_type in GLOB.dna_identity_blocks)
-
+		var/datum/dna_block/identity/block = GLOB.dna_identity_blocks[block_type]
-	//ignores TRAIT_AGENDER so that a "real" gender can be stored in the DNA if later use is needed
+		. += block.unique_block(holder)
-	switch(holder.gender)
-		if(MALE)
-			L[DNA_GENDER_BLOCK] = construct_block(G_MALE, GENDERS)
-		if(FEMALE)
-			L[DNA_GENDER_BLOCK] = construct_block(G_FEMALE, GENDERS)
-		if(NEUTER)
-			L[DNA_GENDER_BLOCK] = construct_block(G_NEUTER, GENDERS)
-		else
-			L[DNA_GENDER_BLOCK] = construct_block(G_PLURAL, GENDERS)
-	if(ishuman(holder))
-		var/mob/living/carbon/human/H = holder
-		if(length(SSaccessories.hairstyles_list) == 0 || length(SSaccessories.facial_hairstyles_list) == 0)
-			CRASH("SSaccessories lists are empty, this is bad!")
-
-		L[DNA_HAIRSTYLE_BLOCK] = construct_block(SSaccessories.hairstyles_list.Find(H.hairstyle), length(SSaccessories.hairstyles_list))
-		L[DNA_HAIR_COLOR_BLOCK] = sanitize_hexcolor(H.hair_color, include_crunch = FALSE)
-		L[DNA_FACIAL_HAIRSTYLE_BLOCK] = construct_block(SSaccessories.facial_hairstyles_list.Find(H.facial_hairstyle), length(SSaccessories.facial_hairstyles_list))
-		L[DNA_FACIAL_HAIR_COLOR_BLOCK] = sanitize_hexcolor(H.facial_hair_color, include_crunch = FALSE)
-		L[DNA_SKIN_TONE_BLOCK] = construct_block(GLOB.skin_tones.Find(H.skin_tone), GLOB.skin_tones.len)
-		L[DNA_EYE_COLOR_LEFT_BLOCK] = sanitize_hexcolor(H.eye_color_left, include_crunch = FALSE)
-		L[DNA_EYE_COLOR_RIGHT_BLOCK] = sanitize_hexcolor(H.eye_color_right, include_crunch = FALSE)
-		L[DNA_HAIRSTYLE_GRADIENT_BLOCK] = construct_block(SSaccessories.hair_gradients_list.Find(H.grad_style[GRADIENT_HAIR_KEY]), length(SSaccessories.hair_gradients_list))
-		L[DNA_HAIR_COLOR_GRADIENT_BLOCK] = sanitize_hexcolor(H.grad_color[GRADIENT_HAIR_KEY], include_crunch = FALSE)
-		L[DNA_FACIAL_HAIRSTYLE_GRADIENT_BLOCK] = construct_block(SSaccessories.facial_hair_gradients_list.Find(H.grad_style[GRADIENT_FACIAL_HAIR_KEY]), length(SSaccessories.facial_hair_gradients_list))
-		L[DNA_FACIAL_HAIR_COLOR_GRADIENT_BLOCK] = sanitize_hexcolor(H.grad_color[GRADIENT_FACIAL_HAIR_KEY], include_crunch = FALSE)
-
-	for(var/blocknum in 1 to DNA_UNI_IDENTITY_BLOCKS)
-		. += L[blocknum] || random_string(GET_UI_BLOCK_LEN(blocknum), GLOB.hex_characters)
 
 /datum/dna/proc/generate_unique_features()
 	. = ""
-	var/list/L = new /list(DNA_FEATURE_BLOCKS)
+	for(var/block_type in GLOB.dna_feature_blocks)
-
+		var/datum/dna_block/feature/block = GLOB.dna_feature_blocks[block_type]
-	if(features["mcolor"])
+		if(isnull(features[block.feature_key]))
-		L[DNA_MUTANT_COLOR_BLOCK] = sanitize_hexcolor(features["mcolor"], include_crunch = FALSE)
+			. += random_string(block.block_length, GLOB.hex_characters)
-	if(features["ethcolor"])
+			continue
-		L[DNA_ETHEREAL_COLOR_BLOCK] = sanitize_hexcolor(features["ethcolor"], include_crunch = FALSE)
+		. += block.unique_block(holder)
-	if(features["lizard_markings"])
-		L[DNA_LIZARD_MARKINGS_BLOCK] = construct_block(SSaccessories.lizard_markings_list.Find(features["lizard_markings"]), length(SSaccessories.lizard_markings_list))
-	if(features["tail_cat"])
-		L[DNA_TAIL_BLOCK] = construct_block(SSaccessories.tails_list_felinid.Find(features["tail_cat"]), length(SSaccessories.tails_list_felinid))
-	if(features["tail_lizard"])
-		L[DNA_LIZARD_TAIL_BLOCK] = construct_block(SSaccessories.tails_list_lizard.Find(features["tail_lizard"]), length(SSaccessories.tails_list_lizard))
-	if(features["snout"])
-		L[DNA_SNOUT_BLOCK] = construct_block(SSaccessories.snouts_list.Find(features["snout"]), length(SSaccessories.snouts_list))
-	if(features["horns"])
-		L[DNA_HORNS_BLOCK] = construct_block(SSaccessories.horns_list.Find(features["horns"]), length(SSaccessories.horns_list))
-	if(features["frills"])
-		L[DNA_FRILLS_BLOCK] = construct_block(SSaccessories.frills_list.Find(features["frills"]), length(SSaccessories.frills_list))
-	if(features["spines"])
-		L[DNA_SPINES_BLOCK] = construct_block(SSaccessories.spines_list.Find(features["spines"]), length(SSaccessories.spines_list))
-	if(features["ears"])
-		L[DNA_EARS_BLOCK] = construct_block(SSaccessories.ears_list.Find(features["ears"]), length(SSaccessories.ears_list))
-	if(features["moth_wings"] != "Burnt Off")
-		L[DNA_MOTH_WINGS_BLOCK] = construct_block(SSaccessories.moth_wings_list.Find(features["moth_wings"]), length(SSaccessories.moth_wings_list))
-	if(features["moth_antennae"] != "Burnt Off")
-		L[DNA_MOTH_ANTENNAE_BLOCK] = construct_block(SSaccessories.moth_antennae_list.Find(features["moth_antennae"]), length(SSaccessories.moth_antennae_list))
-	if(features["moth_markings"])
-		L[DNA_MOTH_MARKINGS_BLOCK] = construct_block(SSaccessories.moth_markings_list.Find(features["moth_markings"]), length(SSaccessories.moth_markings_list))
-	if(features["caps"])
-		L[DNA_MUSHROOM_CAPS_BLOCK] = construct_block(SSaccessories.caps_list.Find(features["caps"]), length(SSaccessories.caps_list))
-	if(features["pod_hair"])
-		L[DNA_POD_HAIR_BLOCK] = construct_block(SSaccessories.pod_hair_list.Find(features["pod_hair"]), length(SSaccessories.pod_hair_list))
-	if(features["fish_tail"])
-		L[DNA_FISH_TAIL_BLOCK] = construct_block(SSaccessories.tails_list_fish.Find(features["fish_tail"]), length(SSaccessories.tails_list_fish))
-
-	for(var/blocknum in 1 to DNA_FEATURE_BLOCKS)
-		. += L[blocknum] || random_string(GET_UI_BLOCK_LEN(blocknum), GLOB.hex_characters)
 
 /**
  * Picks what mutations this DNA has innate and generates DNA blocks for them
@@ -341,96 +256,27 @@ GLOBAL_LIST_INIT(total_uf_len_by_block, populate_total_uf_len_by_block())
 		. += random_string(DNA_UNIQUE_ENZYMES_LEN, GLOB.hex_characters)
 	return .
 
-///Setter macro used to modify unique identity blocks.
-/datum/dna/proc/set_uni_identity_block(blocknum, input)
-	var/precesing_blocks = copytext(unique_identity, 1, GLOB.total_ui_len_by_block[blocknum])
-	var/succeeding_blocks = blocknum < GLOB.total_ui_len_by_block.len ? copytext(unique_identity, GLOB.total_ui_len_by_block[blocknum+1]) : ""
-	unique_identity = precesing_blocks + input + succeeding_blocks
-
 ///Setter macro used to modify unique features blocks.
 /datum/dna/proc/set_uni_feature_block(blocknum, input)
 	var/precesing_blocks = copytext(unique_features, 1, GLOB.total_uf_len_by_block[blocknum])
 	var/succeeding_blocks = blocknum < GLOB.total_uf_len_by_block.len ? copytext(unique_features, GLOB.total_uf_len_by_block[blocknum+1]) : ""
 	unique_features = precesing_blocks + input + succeeding_blocks
 
-/datum/dna/proc/update_ui_block(blocknumber)
+/datum/dna/proc/update_ui_block(blocktype)
-	if(!blocknumber)
+	if(isnull(blocktype))
-		CRASH("UI block index is null")
+		CRASH("UI block type is null")
 	if(!ishuman(holder))
 		CRASH("Non-human mobs shouldn't have DNA")
-	var/mob/living/carbon/human/H = holder
+	var/datum/dna_block/identity/block = GLOB.dna_identity_blocks[blocktype]
-	switch(blocknumber)
+	unique_identity = block.modified_hash(unique_identity, block.unique_block(holder))
-		if(DNA_HAIR_COLOR_BLOCK)
-			set_uni_identity_block(blocknumber, sanitize_hexcolor(H.hair_color, include_crunch = FALSE))
-		if(DNA_FACIAL_HAIR_COLOR_BLOCK)
-			set_uni_identity_block(blocknumber, sanitize_hexcolor(H.facial_hair_color, include_crunch = FALSE))
-		if(DNA_SKIN_TONE_BLOCK)
-			set_uni_identity_block(blocknumber, construct_block(GLOB.skin_tones.Find(H.skin_tone), GLOB.skin_tones.len))
-		if(DNA_EYE_COLOR_LEFT_BLOCK)
-			set_uni_identity_block(blocknumber, sanitize_hexcolor(H.eye_color_left, include_crunch = FALSE))
-		if(DNA_EYE_COLOR_RIGHT_BLOCK)
-			set_uni_identity_block(blocknumber, sanitize_hexcolor(H.eye_color_right, include_crunch = FALSE))
-		if(DNA_GENDER_BLOCK)
-			switch(H.gender)
-				if(MALE)
-					set_uni_identity_block(blocknumber, construct_block(G_MALE, GENDERS))
-				if(FEMALE)
-					set_uni_identity_block(blocknumber, construct_block(G_FEMALE, GENDERS))
-				if(NEUTER)
-					set_uni_identity_block(blocknumber, construct_block(G_NEUTER, GENDERS))
-				else
-					set_uni_identity_block(blocknumber, construct_block(G_PLURAL, GENDERS))
-		if(DNA_FACIAL_HAIRSTYLE_BLOCK)
-			set_uni_identity_block(blocknumber, construct_block(SSaccessories.facial_hairstyles_list.Find(H.facial_hairstyle), length(SSaccessories.facial_hairstyles_list)))
-		if(DNA_HAIRSTYLE_BLOCK)
-			set_uni_identity_block(blocknumber, construct_block(SSaccessories.hairstyles_list.Find(H.hairstyle), length(SSaccessories.hairstyles_list)))
-		if(DNA_HAIRSTYLE_GRADIENT_BLOCK)
-			set_uni_identity_block(blocknumber, construct_block(SSaccessories.hair_gradients_list.Find(H.grad_style[GRADIENT_HAIR_KEY]), length(SSaccessories.hair_gradients_list)))
-		if(DNA_FACIAL_HAIRSTYLE_GRADIENT_BLOCK)
-			set_uni_identity_block(blocknumber, construct_block(SSaccessories.facial_hair_gradients_list.Find(H.grad_style[GRADIENT_FACIAL_HAIR_KEY]), length(SSaccessories.facial_hair_gradients_list)))
-		if(DNA_HAIR_COLOR_GRADIENT_BLOCK)
-			set_uni_identity_block(blocknumber, sanitize_hexcolor(H.grad_color[GRADIENT_HAIR_KEY], include_crunch = FALSE))
-		if(DNA_FACIAL_HAIR_COLOR_GRADIENT_BLOCK)
-			set_uni_identity_block(blocknumber, sanitize_hexcolor(H.grad_color[GRADIENT_FACIAL_HAIR_KEY], include_crunch = FALSE))
 
-/datum/dna/proc/update_uf_block(blocknumber)
+/datum/dna/proc/update_uf_block(blocktype)
-	if(!blocknumber)
+	if(!blocktype)
-		CRASH("UF block index is null")
+		CRASH("UF block type is null")
 	if(!ishuman(holder))
 		CRASH("Non-human mobs shouldn't have DNA")
-	switch(blocknumber)
+	var/datum/dna_block/feature/block = GLOB.dna_identity_blocks[blocktype]
-		if(DNA_MUTANT_COLOR_BLOCK)
+	unique_features = block.modified_hash(unique_features, block.unique_block(holder))
-			set_uni_feature_block(blocknumber, sanitize_hexcolor(features["mcolor"], include_crunch = FALSE))
-		if(DNA_ETHEREAL_COLOR_BLOCK)
-			set_uni_feature_block(blocknumber, sanitize_hexcolor(features["ethcolor"], include_crunch = FALSE))
-		if(DNA_LIZARD_MARKINGS_BLOCK)
-			set_uni_feature_block(blocknumber, construct_block(SSaccessories.lizard_markings_list.Find(features["lizard_markings"]), length(SSaccessories.lizard_markings_list)))
-		if(DNA_TAIL_BLOCK)
-			set_uni_feature_block(blocknumber, construct_block(SSaccessories.tails_list_felinid.Find(features["tail_cat"]), length(SSaccessories.tails_list_felinid)))
-		if(DNA_LIZARD_TAIL_BLOCK)
-			set_uni_feature_block(blocknumber, construct_block(SSaccessories.tails_list_lizard.Find(features["tail_lizard"]), length(SSaccessories.tails_list_lizard)))
-		if(DNA_SNOUT_BLOCK)
-			set_uni_feature_block(blocknumber, construct_block(SSaccessories.snouts_list.Find(features["snout"]), length(SSaccessories.snouts_list)))
-		if(DNA_HORNS_BLOCK)
-			set_uni_feature_block(blocknumber, construct_block(SSaccessories.horns_list.Find(features["horns"]), length(SSaccessories.horns_list)))
-		if(DNA_FRILLS_BLOCK)
-			set_uni_feature_block(blocknumber, construct_block(SSaccessories.frills_list.Find(features["frills"]), length(SSaccessories.frills_list)))
-		if(DNA_SPINES_BLOCK)
-			set_uni_feature_block(blocknumber, construct_block(SSaccessories.spines_list.Find(features["spines"]), length(SSaccessories.spines_list)))
-		if(DNA_EARS_BLOCK)
-			set_uni_feature_block(blocknumber, construct_block(SSaccessories.ears_list.Find(features["ears"]), length(SSaccessories.ears_list)))
-		if(DNA_MOTH_WINGS_BLOCK)
-			set_uni_feature_block(blocknumber, construct_block(SSaccessories.moth_wings_list.Find(features["moth_wings"]), length(SSaccessories.moth_wings_list)))
-		if(DNA_MOTH_ANTENNAE_BLOCK)
-			set_uni_feature_block(blocknumber, construct_block(SSaccessories.moth_antennae_list.Find(features["moth_antennae"]), length(SSaccessories.moth_antennae_list)))
-		if(DNA_MOTH_MARKINGS_BLOCK)
-			set_uni_feature_block(blocknumber, construct_block(SSaccessories.moth_markings_list.Find(features["moth_markings"]), length(SSaccessories.moth_markings_list)))
-		if(DNA_MUSHROOM_CAPS_BLOCK)
-			set_uni_feature_block(blocknumber, construct_block(SSaccessories.caps_list.Find(features["caps"]), length(SSaccessories.caps_list)))
-		if(DNA_POD_HAIR_BLOCK)
-			set_uni_feature_block(blocknumber, construct_block(SSaccessories.pod_hair_list.Find(features["pod_hair"]), length(SSaccessories.pod_hair_list)))
-		if(DNA_FISH_TAIL_BLOCK)
-			set_uni_feature_block(blocknumber, construct_block(SSaccessories.tails_list_fish.Find(features["fish_tail"]), length(SSaccessories.tails_list_fish)))
 
 /**
  * Checks if two DNAs are practically the same by comparing their most defining features
@@ -480,6 +326,8 @@ GLOBAL_LIST_INIT(total_uf_len_by_block, populate_total_uf_len_by_block())
 
 /// Updates the UI, UE, and UF of the DNA according to the features, appearance, name, etc. of the DNA / holder.
 /datum/dna/proc/update_dna_identity()
+	if(!holder.has_dna())
+		return
 	unique_identity = generate_unique_identity()
 	unique_enzymes = generate_unique_enzymes()
 	unique_features = generate_unique_features()
@@ -502,7 +350,7 @@ GLOBAL_LIST_INIT(total_uf_len_by_block, populate_total_uf_len_by_block())
 			for(var/feature in new_features)
 				features[feature] = new_features[feature]
 
-		features["mcolor"] = "#[random_color()]"
+		features[FEATURE_MUTANT_COLOR] = "#[random_color()]"
 
 	update_dna_identity()
 
@@ -636,88 +484,25 @@ GLOBAL_LIST_INIT(total_uf_len_by_block, populate_total_uf_len_by_block())
 		dna.species = new rando_race()
 
 //proc used to update the mob's appearance after its dna UI has been changed
-/mob/living/carbon/proc/updateappearance(icon_update=1, mutcolor_update=0, mutations_overlay_update=0)
+//2025: Im unsure if dna is meant to be living, carbon, or human level.. there's contradicting stuff and bugfixes going back 8 years
+//If youre reading this, and you know for sure, update this, or maybe remove the carbon part entirely
+/mob/living/carbon/proc/updateappearance(icon_update = TRUE, mutcolor_update = FALSE, mutations_overlay_update = FALSE)
 	if(!has_dna())
 		return
 
-	//Always plural gender if agender
-	if(HAS_TRAIT(src, TRAIT_AGENDER))
-		gender = PLURAL
-		return
-
-	switch(deconstruct_block(get_uni_identity_block(dna.unique_identity, DNA_GENDER_BLOCK), GENDERS))
-		if(G_MALE)
-			gender = MALE
-		if(G_FEMALE)
-			gender = FEMALE
-		if(G_NEUTER)
-			gender = NEUTER
-		else
-			gender = PLURAL
-
 /mob/living/carbon/human/updateappearance(icon_update = TRUE, mutcolor_update = FALSE, mutations_overlay_update = FALSE)
-	..()
+	. = ..()
-	var/structure = dna.unique_identity
+	for(var/block_type in GLOB.dna_identity_blocks)
-	skin_tone = GLOB.skin_tones[deconstruct_block(get_uni_identity_block(structure, DNA_SKIN_TONE_BLOCK), GLOB.skin_tones.len)]
+		var/datum/dna_block/identity/block_to_apply = GLOB.dna_identity_blocks[block_type]
-	set_eye_color(sanitize_hexcolor(get_uni_identity_block(structure, DNA_EYE_COLOR_LEFT_BLOCK)), sanitize_hexcolor(get_uni_identity_block(structure, DNA_EYE_COLOR_RIGHT_BLOCK)))
+		block_to_apply.apply_to_mob(src, dna.unique_identity)
-	set_haircolor(sanitize_hexcolor(get_uni_identity_block(structure, DNA_HAIR_COLOR_BLOCK)), update = FALSE)
+
-	set_facial_haircolor(sanitize_hexcolor(get_uni_identity_block(structure, DNA_FACIAL_HAIR_COLOR_BLOCK)), update = FALSE)
+	for(var/block_type in GLOB.dna_feature_blocks)
-	set_hair_gradient_color(sanitize_hexcolor(get_uni_identity_block(structure, DNA_HAIR_COLOR_GRADIENT_BLOCK)), update = FALSE)
+		var/datum/dna_block/feature/block_to_apply = GLOB.dna_feature_blocks[block_type]
-	set_facial_hair_gradient_color(sanitize_hexcolor(get_uni_identity_block(structure, DNA_FACIAL_HAIR_COLOR_GRADIENT_BLOCK)), update = FALSE)
+		if(dna.features[block_to_apply.feature_key])
-	if(HAS_TRAIT(src, TRAIT_SHAVED))
+			block_to_apply.apply_to_mob(src, dna.unique_features)
-		set_facial_hairstyle("Shaved", update = FALSE)
-	else
-		var/style = SSaccessories.facial_hairstyles_list[deconstruct_block(get_uni_identity_block(structure, DNA_FACIAL_HAIRSTYLE_BLOCK), length(SSaccessories.facial_hairstyles_list))]
-		var/gradient_style = SSaccessories.facial_hair_gradients_list[deconstruct_block(get_uni_identity_block(structure, DNA_FACIAL_HAIRSTYLE_GRADIENT_BLOCK), length(SSaccessories.facial_hair_gradients_list))]
-		set_facial_hairstyle(style, update = FALSE)
-		set_facial_hair_gradient_style(gradient_style, update = FALSE)
-	if(HAS_TRAIT(src, TRAIT_BALD))
-		set_hairstyle("Bald", update = FALSE)
-	else
-		var/style = SSaccessories.hairstyles_list[deconstruct_block(get_uni_identity_block(structure, DNA_HAIRSTYLE_BLOCK), length(SSaccessories.hairstyles_list))]
-		var/gradient_style = SSaccessories.hair_gradients_list[deconstruct_block(get_uni_identity_block(structure, DNA_HAIRSTYLE_GRADIENT_BLOCK), length(SSaccessories.hair_gradients_list))]
-		set_hairstyle(style, update = FALSE)
-		set_hair_gradient_style(gradient_style, update = FALSE)
-	var/features = dna.unique_features
-	if(dna.features["mcolor"])
-		dna.features["mcolor"] = sanitize_hexcolor(get_uni_feature_block(features, DNA_MUTANT_COLOR_BLOCK))
-	if(dna.features["ethcolor"])
-		dna.features["ethcolor"] = sanitize_hexcolor(get_uni_feature_block(features, DNA_ETHEREAL_COLOR_BLOCK))
-	if(dna.features["lizard_markings"])
-		dna.features["lizard_markings"] = SSaccessories.lizard_markings_list[deconstruct_block(get_uni_feature_block(features, DNA_LIZARD_MARKINGS_BLOCK), length(SSaccessories.lizard_markings_list))]
-	if(dna.features["snout"])
-		dna.features["snout"] = SSaccessories.snouts_list[deconstruct_block(get_uni_feature_block(features, DNA_SNOUT_BLOCK), length(SSaccessories.snouts_list))]
-	if(dna.features["horns"])
-		dna.features["horns"] = SSaccessories.horns_list[deconstruct_block(get_uni_feature_block(features, DNA_HORNS_BLOCK), length(SSaccessories.horns_list))]
-	if(dna.features["frills"])
-		dna.features["frills"] = SSaccessories.frills_list[deconstruct_block(get_uni_feature_block(features, DNA_FRILLS_BLOCK), length(SSaccessories.frills_list))]
-	if(dna.features["spines"])
-		dna.features["spines"] = SSaccessories.spines_list[deconstruct_block(get_uni_feature_block(features, DNA_SPINES_BLOCK), length(SSaccessories.spines_list))]
-	if(dna.features["tail_cat"])
-		dna.features["tail_cat"] = SSaccessories.tails_list_felinid[deconstruct_block(get_uni_feature_block(features, DNA_TAIL_BLOCK), length(SSaccessories.tails_list_felinid))]
-	if(dna.features["tail_lizard"])
-		dna.features["tail_lizard"] = SSaccessories.tails_list_lizard[deconstruct_block(get_uni_feature_block(features, DNA_LIZARD_TAIL_BLOCK), length(SSaccessories.tails_list_lizard))]
-	if(dna.features["ears"])
-		dna.features["ears"] = SSaccessories.ears_list[deconstruct_block(get_uni_feature_block(features, DNA_EARS_BLOCK), length(SSaccessories.ears_list))]
-	if(dna.features["moth_wings"])
-		var/genetic_value = SSaccessories.moth_wings_list[deconstruct_block(get_uni_feature_block(features, DNA_MOTH_WINGS_BLOCK), length(SSaccessories.moth_wings_list))]
-		dna.features["original_moth_wings"] = genetic_value
-		dna.features["moth_wings"] = genetic_value
-	if(dna.features["moth_antennae"])
-		var/genetic_value = SSaccessories.moth_antennae_list[deconstruct_block(get_uni_feature_block(features, DNA_MOTH_ANTENNAE_BLOCK), length(SSaccessories.moth_antennae_list))]
-		dna.features["original_moth_antennae"] = genetic_value
-		dna.features["moth_antennae"] = genetic_value
-	if(dna.features["moth_markings"])
-		dna.features["moth_markings"] = SSaccessories.moth_markings_list[deconstruct_block(get_uni_feature_block(features, DNA_MOTH_MARKINGS_BLOCK), length(SSaccessories.moth_markings_list))]
-	if(dna.features["caps"])
-		dna.features["caps"] = SSaccessories.caps_list[deconstruct_block(get_uni_feature_block(features, DNA_MUSHROOM_CAPS_BLOCK), length(SSaccessories.caps_list))]
-	if(dna.features["pod_hair"])
-		dna.features["pod_hair"] = SSaccessories.pod_hair_list[deconstruct_block(get_uni_feature_block(features, DNA_POD_HAIR_BLOCK), length(SSaccessories.pod_hair_list))]
-	if(dna.features["fish_tail"])
-		dna.features["fish_tail"] = SSaccessories.tails_list_fish[deconstruct_block(get_uni_feature_block(features, DNA_FISH_TAIL_BLOCK), length(SSaccessories.tails_list_fish))]
 
 	for(var/obj/item/organ/organ in organs)
-		organ.mutate_feature(features, src)
+		organ.mutate_feature(dna.unique_features, src)
 
 	if(icon_update)
 		update_body(is_creating = mutcolor_update)
@@ -839,15 +624,17 @@ GLOBAL_LIST_INIT(total_uf_len_by_block, populate_total_uf_len_by_block())
 /mob/living/carbon/proc/random_mutate_unique_identity()
 	if(!has_dna())
 		CRASH("[src] does not have DNA")
-	var/num = rand(1, DNA_UNI_IDENTITY_BLOCKS)
+	var/mutblock_path = pick(GLOB.dna_identity_blocks)
-	dna.set_uni_feature_block(num, random_string(GET_UI_BLOCK_LEN(num), GLOB.hex_characters))
+	var/datum/dna_block/identity/mutblock = GLOB.dna_identity_blocks[mutblock_path]
-	updateappearance(mutations_overlay_update=1)
+	dna.unique_identity = mutblock.modified_hash(dna.unique_identity, random_string(mutblock.block_length, GLOB.hex_characters))
+	updateappearance(mutations_overlay_update = TRUE)
 
 /mob/living/carbon/proc/random_mutate_unique_features()
 	if(!has_dna())
 		CRASH("[src] does not have DNA")
-	var/num = rand(1, DNA_FEATURE_BLOCKS)
+	var/mutblock_path = pick(GLOB.dna_feature_blocks)
-	dna.set_uni_feature_block(num, random_string(GET_UF_BLOCK_LEN(num), GLOB.hex_characters))
+	var/datum/dna_block/feature/mutblock = GLOB.dna_feature_blocks[mutblock_path]
+	dna.unique_features = mutblock.modified_hash(dna.unique_features, random_string(mutblock.block_length, GLOB.hex_characters))
 	updateappearance(mutcolor_update = TRUE, mutations_overlay_update = TRUE)
 
 /mob/living/carbon/proc/clean_dna()
@@ -859,7 +646,7 @@ GLOBAL_LIST_INIT(total_uf_len_by_block, populate_total_uf_len_by_block())
 	clean_dna()
 	random_mutate(candidates, difficulty)
 
-/proc/scramble_dna(mob/living/carbon/M, ui=FALSE, se=FALSE, uf=FALSE, probability)
+/proc/scramble_dna(mob/living/carbon/M, ui = FALSE, se = FALSE, uf = FALSE, probability = 100)
 	if(!M.has_dna())
 		CRASH("[M] does not have DNA")
 	if(HAS_TRAIT(M, TRAIT_NO_DNA_SCRAMBLE))
@@ -870,13 +657,15 @@ GLOBAL_LIST_INIT(total_uf_len_by_block, populate_total_uf_len_by_block())
 				M.dna.generate_dna_blocks()
 		M.domutcheck()
 	if(ui)
-		for(var/blocknum in 1 to DNA_UNI_IDENTITY_BLOCKS)
+		for(var/block_id in GLOB.dna_identity_blocks)
+			var/datum/dna_block/identity/block = GLOB.dna_identity_blocks[block_id]
 			if(prob(probability))
-				M.dna.set_uni_feature_block(blocknum, random_string(GET_UI_BLOCK_LEN(blocknum), GLOB.hex_characters))
+				M.dna.unique_identity = block.modified_hash(M.dna.unique_identity, random_string(block.block_length, GLOB.hex_characters))
 	if(uf)
-		for(var/blocknum in 1 to DNA_FEATURE_BLOCKS)
+		for(var/block_id in GLOB.dna_feature_blocks)
+			var/datum/dna_block/feature/block = GLOB.dna_feature_blocks[block_id]
 			if(prob(probability))
-				M.dna.set_uni_feature_block(blocknum, random_string(GET_UF_BLOCK_LEN(blocknum), GLOB.hex_characters))
+				M.dna.unique_identity = block.modified_hash(M.dna.unique_identity, random_string(block.block_length, GLOB.hex_characters))
 	if(ui || uf)
 		M.updateappearance(mutcolor_update=uf, mutations_overlay_update=1)
 
@@ -897,12 +686,6 @@ GLOBAL_LIST_INIT(total_uf_len_by_block, populate_total_uf_len_by_block())
 		value = values
 	return value
 
-/proc/get_uni_identity_block(identity, blocknum)
-	return copytext(identity, GLOB.total_ui_len_by_block[blocknum], LAZYACCESS(GLOB.total_ui_len_by_block, blocknum+1))
-
-/proc/get_uni_feature_block(features, blocknum)
-	return copytext(features, GLOB.total_uf_len_by_block[blocknum], LAZYACCESS(GLOB.total_uf_len_by_block, blocknum+1))
-
 /////////////////////////// DNA HELPER-PROCS
 
 /mob/living/carbon/human/proc/something_horrible(ignore_stability)

code/datums/dna/dna_block.dm

@@ -0,0 +1,69 @@
+// This DNA block system is by no means perfect, and individual (Especially feature) blocks still contain a lot of copypaste
+// It might be worth abstracting these, and compacting all SSaccessories vars that use dna_blocks into a single keyed list
+// That's out of scope for me refactoring DNA, but to be considered for a future atomic change
+
+/// A singleton for handling block-unique functions called by the DNA datum.
+///
+/// You don't need to add a DNA block for every feature.
+/// Only add a new one if you want this feature to be changed via genetics.
+/datum/dna_block
+	/// The length of this block when converted to ascii
+	var/block_length = DNA_BLOCK_SIZE
+
+/// Returns the unique block created from target. To be used for external calls.
+///
+/// Does extra checks to make sure target is valid before calling the internal
+/// `create_unique_block`, don't override this.
+/datum/dna_block/proc/unique_block(mob/living/carbon/human/target)
+	SHOULD_NOT_OVERRIDE(TRUE)
+	if(!ishuman(target))
+		CRASH("Non-human mobs shouldn't have DNA")
+	return create_unique_block(target)
+
+/// Actually creates the unique block from the inputted target.
+/// Not used outside of the type, see `unique_block` instead.
+///
+/// Children should always override this.
+/datum/dna_block/proc/create_unique_block(mob/living/carbon/human/target)
+	PROTECTED_PROC(TRUE)
+	return null
+
+/// The position of this block's string in its hash type
+/datum/dna_block/proc/position_in_hash()
+	return null
+
+/// Takes in the old hash and a string value to change this block to inside the hash.
+///
+/// Returns a new hash with block's value updated
+/datum/dna_block/proc/modified_hash(old_hash, value)
+	var/block_pos = position_in_hash()
+	if(isnull(block_pos))
+		return old_hash
+	var/preceding_blocks = copytext(old_hash, 1, block_pos)
+	var/succeeding_blocks = copytext(old_hash, block_pos + block_length)
+	return (preceding_blocks + value + succeeding_blocks)
+
+/// Gets the block string from the hash inserted
+/datum/dna_block/proc/get_block(from_hash)
+	if(isnull(from_hash))
+		CRASH("Null hash provided for getting dna block string")
+	var/block_pos = position_in_hash()
+	return copytext(from_hash, block_pos, block_pos + block_length)
+
+/// Applies the DNA effects/appearance that this block's string encodes
+/datum/dna_block/proc/apply_to_mob(mob/living/carbon/human/target, dna_hash)
+	return
+
+/// Blocks for unique identities (skin tones, hair style, and gender)
+/datum/dna_block/identity
+
+/datum/dna_block/identity/position_in_hash()
+	return GLOB.total_ui_len_by_block[type]
+
+/// Blocks for unique features (mutant color, mutant bodyparts)
+/datum/dna_block/feature
+	/// The feature key this block ties in to.
+	var/feature_key = null
+
+/datum/dna_block/feature/position_in_hash()
+	return GLOB.total_uf_len_by_block[type]

code/datums/quirks/neutral_quirks/heretochromatic.dm

@@ -20,7 +20,7 @@
 	var/was_not_hetero = !human_holder.eye_color_heterochromatic
 	human_holder.eye_color_heterochromatic = TRUE
 	human_holder.eye_color_right = color
-	human_holder.dna.update_ui_block(DNA_EYE_COLOR_RIGHT_BLOCK)
+	human_holder.dna.update_ui_block(/datum/dna_block/identity/eye_colors)
 
 	var/obj/item/organ/eyes/eyes_of_the_holder = quirk_holder.get_organ_by_type(/obj/item/organ/eyes)
 	if(!eyes_of_the_holder)

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

@@ -220,7 +220,7 @@
 	greyscale_colors = FISH_ORGAN_COLOR
 
 	bodypart_overlay = /datum/bodypart_overlay/mutant/tail/fish
-	dna_block = DNA_FISH_TAIL_BLOCK
+	dna_block = /datum/dna_block/feature/tail_fish
 	wag_flags = NONE
 	organ_traits = list(TRAIT_FLOPPING, TRAIT_SWIMMER)
 	restyle_flags = EXTERNAL_RESTYLE_FLESH
@@ -282,15 +282,15 @@
 		source.add_traits(list(TRAIT_OFF_BALANCE_TACKLER, TRAIT_NO_STAGGER, TRAIT_NO_THROW_HITPUSH), type)
 
 /datum/bodypart_overlay/mutant/tail/fish
-	feature_key = "fish_tail"
+	feature_key = FEATURE_TAIL_FISH
 	color_source = ORGAN_COLOR_OVERRIDE
 
 /datum/bodypart_overlay/mutant/tail/fish/on_mob_insert(obj/item/organ/parent, mob/living/carbon/receiver)
 	//Initialize the related dna feature block if we don't have any so it doesn't error out.
 	//This isn't tied to any species, but I kinda want it to be mutable instead of having a fixed sprite accessory.
-	if(imprint_on_next_insertion && !receiver.dna.features["fish_tail"])
+	if(imprint_on_next_insertion && !receiver.dna.features[FEATURE_TAIL_FISH])
-		receiver.dna.features["fish_tail"] = pick(SSaccessories.tails_list_fish)
+		receiver.dna.features[FEATURE_TAIL_FISH] = pick(SSaccessories.tails_list_fish)
-		receiver.dna.update_uf_block(DNA_FISH_TAIL_BLOCK)
+		receiver.dna.update_uf_block(FEATURE_TAIL_FISH)
 
 	return ..()
 

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

@@ -6,6 +6,6 @@
 	visual = TRUE
 	damage_multiplier = 2
 
-	dna_block = DNA_EARS_BLOCK
+	dna_block = /datum/dna_block/feature/ears
 	bodypart_overlay = /datum/bodypart_overlay/mutant/cat_ears
 	sprite_accessory_override = /datum/sprite_accessory/ears/fox

code/game/objects/structures/mirror.dm

@@ -199,15 +199,15 @@ MAPPING_DIRECTIONAL_HELPERS(/obj/structure/mirror/broken, 28)
 		var/new_s_tone = tgui_input_list(race_changer, "Choose your skin tone", "Race change", GLOB.skin_tones)
 		if(new_s_tone)
 			race_changer.skin_tone = new_s_tone
-			race_changer.dna.update_ui_block(DNA_SKIN_TONE_BLOCK)
+			race_changer.dna.update_ui_block(/datum/dna_block/identity/skin_tone)
 	else if(HAS_TRAIT(race_changer, TRAIT_MUTANT_COLORS) && !HAS_TRAIT(race_changer, TRAIT_FIXED_MUTANT_COLORS))
-		var/new_mutantcolor = input(race_changer, "Choose your skin color:", "Race change", race_changer.dna.features["mcolor"]) as color|null
+		var/new_mutantcolor = input(race_changer, "Choose your skin color:", "Race change", race_changer.dna.features[FEATURE_MUTANT_COLOR]) as color|null
 		if(new_mutantcolor)
 			var/list/mutant_hsv = rgb2hsv(new_mutantcolor)
 
 			if(mutant_hsv[3] >= 50) // mutantcolors must be bright
-				race_changer.dna.features["mcolor"] = sanitize_hexcolor(new_mutantcolor)
+				race_changer.dna.features[FEATURE_MUTANT_COLOR] = sanitize_hexcolor(new_mutantcolor)
-				race_changer.dna.update_uf_block(DNA_MUTANT_COLOR_BLOCK)
+				race_changer.dna.update_uf_block(FEATURE_MUTANT_COLOR)
 			else
 				to_chat(race_changer, span_notice("Invalid color. Your color is not bright enough."))
 				return TRUE
@@ -241,7 +241,7 @@ MAPPING_DIRECTIONAL_HELPERS(/obj/structure/mirror/broken, 28)
 	if(chosen_physique && chosen_physique != "Wizards Don't Need Gender")
 		sexy.physique = (chosen_physique == "Warlock Physique") ? MALE : FEMALE
 
-	sexy.dna.update_ui_block(DNA_GENDER_BLOCK)
+	sexy.dna.update_ui_block(/datum/dna_block/identity/gender)
 	sexy.update_body(is_creating = TRUE) // or else physique won't change properly
 	sexy.update_mutations_overlay() //(hulk male/female)
 	sexy.update_clothing(ITEM_SLOT_ICLOTHING) // update gender shaped clothing
@@ -251,8 +251,7 @@ MAPPING_DIRECTIONAL_HELPERS(/obj/structure/mirror/broken, 28)
 	if(isnull(new_eye_color))
 		return TRUE
 	user.set_eye_color(sanitize_hexcolor(new_eye_color))
-	user.dna.update_ui_block(DNA_EYE_COLOR_LEFT_BLOCK)
+	user.dna.update_ui_block(/datum/dna_block/identity/eye_colors)
-	user.dna.update_ui_block(DNA_EYE_COLOR_RIGHT_BLOCK)
 	user.update_body()
 	to_chat(user, span_notice("You gaze at your new eyes with your new eyes. Perfect!"))
 
@@ -383,12 +382,12 @@ MAPPING_DIRECTIONAL_HELPERS(/obj/structure/mirror/broken, 28)
 
 	if(new_hair_color)
 		user.set_haircolor(sanitize_hexcolor(new_hair_color))
-		user.dna.update_ui_block(DNA_HAIR_COLOR_BLOCK)
+		user.dna.update_ui_block(/datum/dna_block/identity/hair_color)
 	if(user.physique == MALE)
 		var/new_face_color = input(user, "Choose your facial hair color", "Hair Color", user.facial_hair_color) as color|null
 		if(new_face_color)
 			user.set_facial_haircolor(sanitize_hexcolor(new_face_color))
-			user.dna.update_ui_block(DNA_FACIAL_HAIR_COLOR_BLOCK)
+			user.dna.update_ui_block(/datum/dna_block/identity/facial_color)
 
 /obj/structure/mirror/magic/attack_hand(mob/living/carbon/human/user)
 	. = ..()

code/modules/admin/verbs/secrets.dm

@@ -578,7 +578,7 @@ ADMIN_VERB(secrets, R_NONE, "Secrets", "Abuse harder than you ever have before w
 				SEND_SOUND(H, sound(SSstation.announcer.event_sounds[ANNOUNCER_ANIMES]))
 
 				if(H.dna.species.id == SPECIES_HUMAN)
-					if(H.dna.features["tail_human"] == "None" || H.dna.features["ears"] == "None")
+					if(H.dna.features[FEATURE_TAIL] == "None" || H.dna.features[FEATURE_EARS] == "None")
 						var/obj/item/organ/ears/cat/ears = new
 						var/obj/item/organ/tail/cat/tail = new
 						ears.Insert(H, movement_flags = DELETE_IF_REPLACED)

code/modules/antagonists/brother/brother.dm

@@ -133,12 +133,12 @@
 	var/mob/living/carbon/human/dummy/consistent/brother1 = new
 	var/mob/living/carbon/human/dummy/consistent/brother2 = new
 
-	brother1.dna.features["ethcolor"] = GLOB.color_list_ethereal["Faint Red"]
+	brother1.dna.features[FEATURE_ETHEREAL_COLOR] = GLOB.color_list_ethereal["Faint Red"]
 	brother1.set_species(/datum/species/ethereal)
 
-	brother2.dna.features["moth_antennae"] = "Plain"
+	brother2.dna.features[FEATURE_MOTH_ANTENNAE] = "Plain"
-	brother2.dna.features["moth_markings"] = "None"
+	brother2.dna.features[FEATURE_MOTH_MARKINGS] = "None"
-	brother2.dna.features["moth_wings"] = "Plain"
+	brother2.dna.features[FEATURE_MOTH_WINGS] = "Plain"
 	brother2.set_species(/datum/species/moth)
 
 	var/icon/brother1_icon = render_preview_outfit(/datum/outfit/job/quartermaster, brother1)

code/modules/client/preferences/species_features/ethereal.dm

@@ -33,4 +33,4 @@
 	return icon
 
 /datum/preference/choiced/ethereal_color/apply_to_human(mob/living/carbon/human/target, value)
-	target.dna.features["ethcolor"] = GLOB.color_list_ethereal[value]
+	target.dna.features[FEATURE_ETHEREAL_COLOR] = GLOB.color_list_ethereal[value]

code/modules/client/preferences/species_features/felinid.dm

@@ -9,7 +9,7 @@
 	return assoc_to_keys_features(SSaccessories.tails_list_felinid)
 
 /datum/preference/choiced/tail_felinid/apply_to_human(mob/living/carbon/human/target, value)
-	target.dna.features["tail_cat"] = value
+	target.dna.features[FEATURE_TAIL] = value
 
 /datum/preference/choiced/tail_felinid/create_default_value()
 	var/datum/sprite_accessory/tails/felinid/cat/tail = /datum/sprite_accessory/tails/felinid/cat
@@ -26,7 +26,7 @@
 	return assoc_to_keys_features(SSaccessories.ears_list)
 
 /datum/preference/choiced/felinid_ears/apply_to_human(mob/living/carbon/human/target, value)
-	target.dna.features["ears"] = value
+	target.dna.features[FEATURE_EARS] = value
 
 /datum/preference/choiced/felinid_ears/create_default_value()
 	return /datum/sprite_accessory/ears/cat::name

code/modules/client/preferences/species_features/lizard.dm

@@ -55,7 +55,7 @@
 	return final_icon
 
 /datum/preference/choiced/lizard_body_markings/apply_to_human(mob/living/carbon/human/target, value)
-	target.dna.features["lizard_markings"] = value
+	target.dna.features[FEATURE_LIZARD_MARKINGS] = value
 
 /datum/preference/choiced/lizard_frills
 	savefile_key = "feature_lizard_frills"
@@ -72,7 +72,7 @@
 	return generate_lizard_side_shot(SSaccessories.frills_list[value], "frills")
 
 /datum/preference/choiced/lizard_frills/apply_to_human(mob/living/carbon/human/target, value)
-	target.dna.features["frills"] = value
+	target.dna.features[FEATURE_FRILLS] = value
 
 /datum/preference/choiced/lizard_horns
 	savefile_key = "feature_lizard_horns"
@@ -89,7 +89,7 @@
 	return generate_lizard_side_shot(SSaccessories.horns_list[value], "horns")
 
 /datum/preference/choiced/lizard_horns/apply_to_human(mob/living/carbon/human/target, value)
-	target.dna.features["horns"] = value
+	target.dna.features[FEATURE_HORNS] = value
 
 /datum/preference/choiced/lizard_legs
 	savefile_key = "feature_lizard_legs"
@@ -100,7 +100,7 @@
 	return list(NORMAL_LEGS, DIGITIGRADE_LEGS)
 
 /datum/preference/choiced/lizard_legs/apply_to_human(mob/living/carbon/human/target, value)
-	target.dna.features["legs"] = value
+	target.dna.features[FEATURE_LEGS] = value
 	// Hack to update the dummy in the preference menu
 	// (Because digi legs are ONLY handled on species change)
 	if(!isdummy(target) || target.dna.species.digitigrade_customization == DIGITIGRADE_NEVER)
@@ -145,7 +145,7 @@
 	return generate_lizard_side_shot(SSaccessories.snouts_list[value], "snout", include_snout = FALSE)
 
 /datum/preference/choiced/lizard_snout/apply_to_human(mob/living/carbon/human/target, value)
-	target.dna.features["snout"] = value
+	target.dna.features[FEATURE_SNOUT] = value
 
 /datum/preference/choiced/lizard_spines
 	savefile_key = "feature_lizard_spines"
@@ -157,7 +157,7 @@
 	return assoc_to_keys_features(SSaccessories.spines_list)
 
 /datum/preference/choiced/lizard_spines/apply_to_human(mob/living/carbon/human/target, value)
-	target.dna.features["spines"] = value
+	target.dna.features[FEATURE_SPINES] = value
 
 /datum/preference/choiced/lizard_tail
 	savefile_key = "feature_lizard_tail"
@@ -169,7 +169,7 @@
 	return assoc_to_keys_features(SSaccessories.tails_list_lizard)
 
 /datum/preference/choiced/lizard_tail/apply_to_human(mob/living/carbon/human/target, value)
-	target.dna.features["tail_lizard"] = value
+	target.dna.features[FEATURE_TAIL_LIZARD] = value
 
 /datum/preference/choiced/lizard_tail/create_default_value()
 	return /datum/sprite_accessory/tails/lizard/smooth::name

code/modules/client/preferences/species_features/monkey.dm

@@ -9,7 +9,7 @@
 	return assoc_to_keys_features(SSaccessories.tails_list_monkey)
 
 /datum/preference/choiced/monkey_tail/apply_to_human(mob/living/carbon/human/target, value)
-	target.dna.features["tail_monkey"] = value
+	target.dna.features[FEATURE_TAIL_MONKEY] = value
 
 /datum/preference/choiced/monkey_tail/create_default_value()
 	return /datum/sprite_accessory/tails/monkey/default::name

code/modules/client/preferences/species_features/moth.dm

@@ -27,7 +27,7 @@
 	return icon_with_antennae
 
 /datum/preference/choiced/moth_antennae/apply_to_human(mob/living/carbon/human/target, value)
-	target.dna.features["moth_antennae"] = value
+	target.dna.features[FEATURE_MOTH_ANTENNAE] = value
 
 /datum/preference/choiced/moth_markings
 	savefile_key = "feature_moth_markings"
@@ -77,7 +77,7 @@
 	return icon_with_markings
 
 /datum/preference/choiced/moth_markings/apply_to_human(mob/living/carbon/human/target, value)
-	target.dna.features["moth_markings"] = value
+	target.dna.features[FEATURE_MOTH_MARKINGS] = value
 
 /datum/preference/choiced/moth_wings
 	savefile_key = "feature_moth_wings"
@@ -95,4 +95,4 @@
 	return uni_icon(moth_wings.icon, "m_moth_wings_[moth_wings.icon_state]_BEHIND")
 
 /datum/preference/choiced/moth_wings/apply_to_human(mob/living/carbon/human/target, value)
-	target.dna.features["moth_wings"] = value
+	target.dna.features[FEATURE_MOTH_WINGS] = value

code/modules/client/preferences/species_features/mushperson.dm

@@ -8,4 +8,4 @@
 	return assoc_to_keys_features(SSaccessories.caps_list)
 
 /datum/preference/choiced/mushroom_cap/apply_to_human(mob/living/carbon/human/target, value)
-	target.dna.features["caps"] = value
+	target.dna.features[FEATURE_MUSH_CAP] = value

code/modules/client/preferences/species_features/mutants.dm

@@ -16,7 +16,7 @@
 	return sanitize_hexcolor("[pick("7F", "FF")][pick("7F", "FF")][pick("7F", "FF")]")
 
 /datum/preference/color/mutant_color/apply_to_human(mob/living/carbon/human/target, value)
-	target.dna.features["mcolor"] = value
+	target.dna.features[FEATURE_MUTANT_COLOR] = value
 
 /datum/preference/color/mutant_color/is_valid(value)
 	if (!..(value))

code/modules/client/preferences/species_features/pod.dm

@@ -28,4 +28,4 @@
 	return pick(assoc_to_keys_features(SSaccessories.pod_hair_list))
 
 /datum/preference/choiced/pod_hair/apply_to_human(mob/living/carbon/human/target, value)
-	target.dna.features["pod_hair"] = value
+	target.dna.features[FEATURE_POD_HAIR] = value

code/modules/hydroponics/grown/replicapod.dm

@@ -199,10 +199,10 @@
 
 	podman.gender = blood_gender
 	podman.faction |= factions
-	if(!features["mcolor"])
+	if(!features[FEATURE_MUTANT_COLOR])
-		features["mcolor"] = "#59CE00"
+		features[FEATURE_MUTANT_COLOR] = "#59CE00"
-	if(!features["pod_hair"])
+	if(!features[FEATURE_POD_HAIR])
-		features["pod_hair"] = pick(SSaccessories.pod_hair_list)
+		features[FEATURE_POD_HAIR] = pick(SSaccessories.pod_hair_list)
 
 	for(var/V in quirks)
 		new V(podman)

code/modules/mining/lavaland/mining_loot/megafauna/ash_drake.dm

@@ -171,17 +171,17 @@
 		if(1)
 			to_chat(user, span_danger("Your appearance morphs to that of a very small humanoid ash dragon! You get to look like a freak without the cool abilities."))
 			consumer.dna.features = list(
-				"mcolor" = "#A02720",
+				FEATURE_MUTANT_COLOR = "#A02720",
-				"tail_lizard" = "Dark Tiger",
+				FEATURE_TAIL_LIZARD = "Dark Tiger",
-				"tail_human" = "None",
+				FEATURE_TAIL = "None",
-				"snout" = "Sharp",
+				FEATURE_SNOUT = "Sharp",
-				"horns" = "Curled",
+				FEATURE_HORNS = "Curled",
-				"ears" = "None",
+				FEATURE_EARS = "None",
-				"wings" = "None",
+				FEATURE_WINGS = "None",
-				"frills" = "None",
+				FEATURE_FRILLS = "None",
-				"spines" = "Long",
+				FEATURE_SPINES = "Long",
-				"lizard_markings" = "Dark Tiger Body",
+				FEATURE_LIZARD_MARKINGS = "Dark Tiger Body",
-				"legs" = DIGITIGRADE_LEGS,
+				FEATURE_LEGS = DIGITIGRADE_LEGS,
 			)
 			consumer.set_eye_color("#FEE5A3")
 			consumer.set_species(/datum/species/lizard)

code/modules/mob/living/blood_types.dm

@@ -350,9 +350,9 @@
 
 // Ensures that lighter slimefolk look half-decent when wounded and bleeding
 /datum/blood_type/slime/get_wound_color(mob/living/carbon/victim)
-	return victim.dna?.features?["mcolor"] || get_color()
+	return victim.dna?.features?[FEATURE_MUTANT_COLOR] || get_color()
 /datum/blood_type/slime/get_damage_color(mob/living/carbon/victim)
-	return victim.dna?.features?["mcolor"] || get_color()
+	return victim.dna?.features?[FEATURE_MUTANT_COLOR] || get_color()
 
 /// Podpeople blood
 /datum/blood_type/water

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

@@ -1996,7 +1996,7 @@ GLOBAL_LIST_EMPTY(features_by_species)
 	//Note for future: Potentionally add a new C.dna.species() to build a template species for more accurate limb replacement
 
 	var/list/final_bodypart_overrides = new_species.bodypart_overrides.Copy()
-	if((new_species.digitigrade_customization == DIGITIGRADE_OPTIONAL && target.dna.features["legs"] == DIGITIGRADE_LEGS) || new_species.digitigrade_customization == DIGITIGRADE_FORCED)
+	if((new_species.digitigrade_customization == DIGITIGRADE_OPTIONAL && target.dna.features[FEATURE_LEGS] == DIGITIGRADE_LEGS) || new_species.digitigrade_customization == DIGITIGRADE_FORCED)
 		final_bodypart_overrides[BODY_ZONE_R_LEG] = /obj/item/bodypart/leg/right/digitigrade
 		final_bodypart_overrides[BODY_ZONE_L_LEG] = /obj/item/bodypart/leg/left/digitigrade
 
@@ -2048,7 +2048,7 @@ GLOBAL_LIST_EMPTY(features_by_species)
 	ASSERT(!isnull(for_mob))
 	switch(hair_color_mode)
 		if(USE_MUTANT_COLOR)
-			return for_mob.dna.features["mcolor"]
+			return for_mob.dna.features[FEATURE_MUTANT_COLOR]
 		if(USE_FIXED_MUTANT_COLOR)
 			return fixed_mut_color
 
@@ -2065,7 +2065,7 @@ GLOBAL_LIST_EMPTY(features_by_species)
 				continue
 
 			var/datum/bodypart_overlay/simple/body_marking/overlay = new markings_type()
-			overlay.set_appearance(accessory_name, hooman.dna.features["mcolor"])
+			overlay.set_appearance(accessory_name, hooman.dna.features[FEATURE_MUTANT_COLOR])
 			people_part.add_bodypart_overlay(overlay)
 
 		qdel(markings)

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

@@ -105,23 +105,23 @@ INITIALIZE_IMMEDIATE(/mob/living/carbon/human/dummy)
 	return consistent_entry
 
 /proc/create_consistent_human_dna(mob/living/carbon/human/target)
-	target.dna.features["mcolor"] = COLOR_VIBRANT_LIME
+	target.dna.features[FEATURE_MUTANT_COLOR] = COLOR_VIBRANT_LIME
-	target.dna.features["ethcolor"] = COLOR_WHITE
+	target.dna.features[FEATURE_ETHEREAL_COLOR] = COLOR_WHITE
-	target.dna.features["lizard_markings"] = get_consistent_feature_entry(SSaccessories.lizard_markings_list)
+	target.dna.features[FEATURE_LIZARD_MARKINGS] = get_consistent_feature_entry(SSaccessories.lizard_markings_list)
-	target.dna.features["ears"] = get_consistent_feature_entry(SSaccessories.ears_list)
+	target.dna.features[FEATURE_EARS] = get_consistent_feature_entry(SSaccessories.ears_list)
-	target.dna.features["frills"] = get_consistent_feature_entry(SSaccessories.frills_list)
+	target.dna.features[FEATURE_FRILLS] = get_consistent_feature_entry(SSaccessories.frills_list)
-	target.dna.features["horns"] = get_consistent_feature_entry(SSaccessories.horns_list)
+	target.dna.features[FEATURE_HORNS] = get_consistent_feature_entry(SSaccessories.horns_list)
-	target.dna.features["moth_antennae"] = get_consistent_feature_entry(SSaccessories.moth_antennae_list)
+	target.dna.features[FEATURE_MOTH_ANTENNAE] = get_consistent_feature_entry(SSaccessories.moth_antennae_list)
-	target.dna.features["moth_markings"] = get_consistent_feature_entry(SSaccessories.moth_markings_list)
+	target.dna.features[FEATURE_MOTH_MARKINGS] = get_consistent_feature_entry(SSaccessories.moth_markings_list)
-	target.dna.features["moth_wings"] = get_consistent_feature_entry(SSaccessories.moth_wings_list)
+	target.dna.features[FEATURE_MOTH_WINGS] = get_consistent_feature_entry(SSaccessories.moth_wings_list)
-	target.dna.features["snout"] = get_consistent_feature_entry(SSaccessories.snouts_list)
+	target.dna.features[FEATURE_SNOUT] = get_consistent_feature_entry(SSaccessories.snouts_list)
-	target.dna.features["spines"] = get_consistent_feature_entry(SSaccessories.spines_list)
+	target.dna.features[FEATURE_SPINES] = get_consistent_feature_entry(SSaccessories.spines_list)
-	target.dna.features["tail_cat"] = get_consistent_feature_entry(SSaccessories.tails_list_felinid) // it's a lie
+	target.dna.features[FEATURE_TAIL] = get_consistent_feature_entry(SSaccessories.tails_list_felinid) // it's a lie
-	target.dna.features["tail_lizard"] = get_consistent_feature_entry(SSaccessories.tails_list_lizard)
+	target.dna.features[FEATURE_TAIL_LIZARD] = get_consistent_feature_entry(SSaccessories.tails_list_lizard)
-	target.dna.features["tail_monkey"] = get_consistent_feature_entry(SSaccessories.tails_list_monkey)
+	target.dna.features[FEATURE_TAIL_MONKEY] = get_consistent_feature_entry(SSaccessories.tails_list_monkey)
-	target.dna.features["fish_tail"] = get_consistent_feature_entry(SSaccessories.tails_list_fish)
+	target.dna.features[FEATURE_TAIL_FISH] = get_consistent_feature_entry(SSaccessories.tails_list_fish)
-	target.dna.features["pod_hair"] = get_consistent_feature_entry(SSaccessories.pod_hair_list)
+	target.dna.features[FEATURE_POD_HAIR] = get_consistent_feature_entry(SSaccessories.pod_hair_list)
-	target.dna.features["caps"] = get_consistent_feature_entry(SSaccessories.caps_list)
+	target.dna.features[FEATURE_MUSH_CAP] = get_consistent_feature_entry(SSaccessories.caps_list)
 	target.dna.initialize_dna(newblood_type = get_blood_type(BLOOD_TYPE_O_MINUS), create_mutation_blocks = FALSE, randomize_features = FALSE)
 	// UF and UI are nondeterministic, even though the features are the same some blocks will randomize slightly
 	// In practice this doesn't matter, but this is for the sake of 100%(ish) consistency

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

@@ -55,7 +55,7 @@
 	. = ..()
 	if(!ishuman(new_ethereal))
 		return
-	default_color = new_ethereal.dna.features["ethcolor"]
+	default_color = new_ethereal.dna.features[FEATURE_ETHEREAL_COLOR]
 	RegisterSignal(new_ethereal, COMSIG_ATOM_EMAG_ACT, PROC_REF(on_emag_act))
 	RegisterSignal(new_ethereal, COMSIG_ATOM_EMP_ACT, PROC_REF(on_emp_act))
 	RegisterSignal(new_ethereal, COMSIG_ATOM_SABOTEUR_ACT, PROC_REF(hit_by_saboteur))
@@ -84,7 +84,7 @@
 
 /datum/species/ethereal/randomize_features()
 	var/list/features = ..()
-	features["ethcolor"] = GLOB.color_list_ethereal[pick(GLOB.color_list_ethereal)]
+	features[FEATURE_ETHEREAL_COLOR] = GLOB.color_list_ethereal[pick(GLOB.color_list_ethereal)]
 	return features
 
 /datum/species/ethereal/proc/refresh_light_color(mob/living/carbon/human/ethereal)
@@ -95,7 +95,7 @@
 		var/healthpercent = max(ethereal.health, 0) / 100
 		if(!emageffect)
 			var/static/list/skin_color = rgb2num("#eda495")
-			var/list/colors = rgb2num(ethereal.dna.features["ethcolor"])
+			var/list/colors = rgb2num(ethereal.dna.features[FEATURE_ETHEREAL_COLOR])
 			var/list/built_color = list()
 			for(var/i in 1 to 3)
 				built_color += skin_color[i] + ((colors[i] - skin_color[i]) * healthpercent)
@@ -334,5 +334,5 @@
 
 /datum/species/ethereal/lustrous/on_species_gain(mob/living/carbon/new_lustrous, datum/species/old_species, pref_load, regenerate_icons)
 	..()
-	default_color = new_lustrous.dna.features["ethcolor"]
+	default_color = new_lustrous.dna.features[FEATURE_ETHEREAL_COLOR]
-	new_lustrous.dna.features["ethcolor"] = GLOB.color_list_lustrous[pick(GLOB.color_list_lustrous)] //Picks one of 5 lustrous-specific colors.
+	new_lustrous.dna.features[FEATURE_ETHEREAL_COLOR] = GLOB.color_list_lustrous[pick(GLOB.color_list_lustrous)] //Picks one of 5 lustrous-specific colors.

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

@@ -28,19 +28,19 @@
 	if(ishuman(carbon_being))
 		var/mob/living/carbon/human/target_human = carbon_being
 		if(!pref_load) //Hah! They got forcefully purrbation'd. Force default felinid parts on them if they have no mutant parts in those areas!
-			target_human.dna.features["tail_cat"] = "Cat"
+			target_human.dna.features[FEATURE_TAIL] = "Cat"
-			if(target_human.dna.features["ears"] == "None")
+			if(target_human.dna.features[FEATURE_EARS] == "None")
-				target_human.dna.features["ears"] = "Cat"
+				target_human.dna.features[FEATURE_EARS] = "Cat"
-		if(target_human.dna.features["ears"] == "None")
+		if(target_human.dna.features[FEATURE_EARS] == "None")
 			mutantears = /obj/item/organ/ears
 		else
-			var/obj/item/organ/ears/cat/ears = new(FALSE, target_human.dna.features["ears"])
+			var/obj/item/organ/ears/cat/ears = new(FALSE, target_human.dna.features[FEATURE_EARS])
 			ears.Insert(target_human, movement_flags = DELETE_IF_REPLACED)
 	return ..()
 
 /datum/species/human/felinid/randomize_features(mob/living/carbon/human/human_mob)
 	var/list/features = ..()
-	features["ears"] = pick("None", "Cat")
+	features[FEATURE_EARS] = pick("None", "Cat")
 	return features
 
 /datum/species/human/felinid/get_laugh_sound(mob/living/carbon/human/felinid)

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

@@ -107,7 +107,7 @@
 	)
 
 /datum/species/jelly/prepare_human_for_preview(mob/living/carbon/human/human)
-	human.dna.features["mcolor"] = COLOR_PINK
+	human.dna.features[FEATURE_MUTANT_COLOR] = COLOR_PINK
 	human.hairstyle = "Bob Hair 2"
 	human.hair_color = COLOR_PINK
 	human.update_body(is_creating = TRUE)
@@ -304,8 +304,8 @@
 
 	spare.underwear = "Nude"
 	H.dna.copy_dna(spare.dna, COPY_DNA_SE|COPY_DNA_SPECIES|COPY_DNA_MUTATIONS)
-	spare.dna.features["mcolor"] = "#[pick("7F", "FF")][pick("7F", "FF")][pick("7F", "FF")]"
+	spare.dna.features[FEATURE_MUTANT_COLOR] = "#[pick("7F", "FF")][pick("7F", "FF")][pick("7F", "FF")]"
-	spare.dna.update_uf_block(DNA_MUTANT_COLOR_BLOCK)
+	spare.dna.update_uf_block(FEATURE_MUTANT_COLOR)
 	spare.real_name = spare.dna.real_name
 	spare.name = spare.dna.real_name
 	spare.updateappearance(mutcolor_update=1)
@@ -371,7 +371,7 @@
 			continue
 
 		var/list/L = list()
-		L["htmlcolor"] = body.dna.features["mcolor"]
+		L["htmlcolor"] = body.dna.features[FEATURE_MUTANT_COLOR]
 		L["area"] = get_area_name(body, TRUE)
 		var/stat = "error"
 		switch(body.stat)
@@ -541,7 +541,7 @@
 /datum/species/jelly/luminescent/proc/update_glow(mob/living/carbon/human/glowie, intensity)
 	if(intensity)
 		glow_intensity = intensity
-	glow.set_light_range_power_color(glow_intensity, glow_intensity, glowie.dna.features["mcolor"])
+	glow.set_light_range_power_color(glow_intensity, glow_intensity, glowie.dna.features[FEATURE_MUTANT_COLOR])
 
 /datum/action/innate/integrate_extract
 	name = "Integrate Extract"

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

@@ -51,7 +51,7 @@
 
 /datum/species/lizard/randomize_features()
 	var/list/features = ..()
-	features["lizard_markings"] = pick(SSaccessories.lizard_markings_list)
+	features[FEATURE_LIZARD_MARKINGS] = pick(SSaccessories.lizard_markings_list)
 	return features
 
 /datum/species/lizard/get_scream_sound(mob/living/carbon/human/lizard)
@@ -225,14 +225,14 @@ Lizard subspecies: SILVER SCALED
 		and their tongue allows them to turn into a statue, for some reason."
 
 /datum/species/lizard/silverscale/on_species_gain(mob/living/carbon/human/new_silverscale, datum/species/old_species, pref_load, regenerate_icons)
-	old_mutcolor = new_silverscale.dna.features["mcolor"]
+	old_mutcolor = new_silverscale.dna.features[FEATURE_MUTANT_COLOR]
-	new_silverscale.dna.features["mcolor"] = "#eeeeee"
+	new_silverscale.dna.features[FEATURE_MUTANT_COLOR] = "#eeeeee"
 	new_silverscale.add_eye_color("#0000a0", EYE_COLOR_SPECIES_PRIORITY)
 	. = ..()
 	new_silverscale.add_filter("silver_glint", 2, list("type" = "outline", "color" = "#ffffff63", "size" = 2))
 
 /datum/species/lizard/silverscale/on_species_loss(mob/living/carbon/human/was_silverscale, datum/species/new_species, pref_load)
-	was_silverscale.dna.features["mcolor"] = old_mutcolor
+	was_silverscale.dna.features[FEATURE_MUTANT_COLOR] = old_mutcolor
 	was_silverscale.remove_eye_color(EYE_COLOR_SPECIES_PRIORITY)
 	was_silverscale.remove_filter("silver_glint")
 	return ..()

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

@@ -45,7 +45,7 @@
 
 /datum/species/moth/randomize_features()
 	var/list/features = ..()
-	features["moth_markings"] = pick(SSaccessories.moth_markings_list)
+	features[FEATURE_MOTH_MARKINGS] = pick(SSaccessories.moth_markings_list)
 	return features
 
 /datum/species/moth/get_scream_sound(mob/living/carbon/human/moth)

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

@@ -61,7 +61,7 @@
 
 	preference = "feature_mushperson_cap"
 
-	dna_block = DNA_MUSHROOM_CAPS_BLOCK
+	dna_block = /datum/dna_block/feature/mush_cap
 	restyle_flags = EXTERNAL_RESTYLE_PLANT
 
 	bodypart_overlay = /datum/bodypart_overlay/mutant/mushroom_cap
@@ -71,7 +71,7 @@
 /// Bodypart overlay for the mushroom cap organ
 /datum/bodypart_overlay/mutant/mushroom_cap
 	layers = EXTERNAL_ADJACENT
-	feature_key = "caps"
+	feature_key = FEATURE_MUSH_CAP
 	dyable = TRUE
 
 /datum/bodypart_overlay/mutant/mushroom_cap/get_global_feature_list()

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

@@ -40,8 +40,8 @@
 	)
 
 /datum/species/pod/prepare_human_for_preview(mob/living/carbon/human/human)
-	human.dna.features["mcolor"] = "#886600"
+	human.dna.features[FEATURE_MUTANT_COLOR] = "#886600"
-	human.dna.features["pod_hair"] = "Rose"
+	human.dna.features[FEATURE_POD_HAIR] = "Rose"
 	human.update_body(is_creating = TRUE)
 
 /datum/species/pod/get_physical_attributes()

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

@@ -28,7 +28,7 @@
 	)
 
 /datum/species/snail/prepare_human_for_preview(mob/living/carbon/human/human)
-	human.dna.features["mcolor"] = COLOR_BEIGE
+	human.dna.features[FEATURE_MUTANT_COLOR] = COLOR_BEIGE
 	human.update_body(is_creating = TRUE)
 
 /datum/species/snail/get_physical_attributes()

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

@@ -31,14 +31,8 @@
 /mob/living/carbon/proc/on_agender_trait_loss(datum/source)
 	SIGNAL_HANDLER
 
-	//updates our gender to be whatever our DNA wants it to be
+	var/datum/dna_block/identity/gender/to_update = GLOB.dna_identity_blocks[/datum/dna_block/identity/gender]
-	switch(deconstruct_block(get_uni_identity_block(dna.unique_identity, DNA_GENDER_BLOCK), 3) || pick(G_MALE, G_FEMALE))
+	to_update.apply_to_mob(src, src.dna.unique_identity)
-		if(G_MALE)
-			gender = MALE
-		if(G_FEMALE)
-			gender = FEMALE
-		else
-			gender = PLURAL
 
 /**
  * On gain of TRAIT_NOBREATH

code/modules/reagents/chemistry/reagents/drinks/alcohol_reagents.dm

@@ -168,7 +168,7 @@
 	if(HAS_TRAIT(affected_human, TRAIT_USES_SKINTONES))
 		affected_human.skin_tone = "green"
 	else if(HAS_TRAIT(affected_human, TRAIT_MUTANT_COLORS) && !HAS_TRAIT(affected_human, TRAIT_FIXED_MUTANT_COLORS)) //Code stolen from spraytan overdose
-		affected_human.dna.features["mcolor"] = "#a8e61d"
+		affected_human.dna.features[FEATURE_MUTANT_COLOR] = "#a8e61d"
 	affected_human.update_body(is_creating = TRUE)
 
 /datum/reagent/consumable/ethanol/kahlua

code/modules/reagents/chemistry/reagents/other_reagents.dm

@@ -589,7 +589,7 @@
 						exposed_human.skin_tone = "mixed3"
 			//take current alien color and darken it slightly
 			else if(HAS_TRAIT(exposed_human, TRAIT_MUTANT_COLORS) && !HAS_TRAIT(exposed_human, TRAIT_FIXED_MUTANT_COLORS))
-				var/list/existing_color = rgb2num(exposed_human.dna.features["mcolor"])
+				var/list/existing_color = rgb2num(exposed_human.dna.features[FEATURE_MUTANT_COLOR])
 				var/list/darkened_color = list()
 				// Reduces each part of the color by 16
 				for(var/channel in existing_color)
@@ -599,7 +599,7 @@
 				var/list/new_hsv = rgb2hsv(new_color)
 				// Can't get too dark now
 				if(new_hsv[3] >= 50)
-					exposed_human.dna.features["mcolor"] = new_color
+					exposed_human.dna.features[FEATURE_MUTANT_COLOR] = new_color
 			exposed_human.update_body(is_creating = TRUE)
 
 		if((methods & INGEST) && show_message)
@@ -623,7 +623,7 @@
 		if(HAS_TRAIT(affected_human, TRAIT_USES_SKINTONES))
 			affected_human.skin_tone = "orange"
 		else if(HAS_TRAIT(affected_human, TRAIT_MUTANT_COLORS) && !HAS_TRAIT(affected_human, TRAIT_FIXED_MUTANT_COLORS)) //Aliens with custom colors simply get turned orange
-			affected_human.dna.features["mcolor"] = "#ff8800"
+			affected_human.dna.features[FEATURE_MUTANT_COLOR] = "#ff8800"
 		affected_human.update_body(is_creating = TRUE)
 		if(SPT_PROB(3.5, seconds_per_tick))
 			if(affected_human.w_uniform)

code/modules/research/xenobiology/xenobiology.dm

@@ -606,8 +606,8 @@
 /obj/item/slime_extract/rainbow/activate(mob/living/carbon/human/user, datum/species/jelly/luminescent/species, activation_type)
 	switch(activation_type)
 		if(SLIME_ACTIVATE_MINOR)
-			user.dna.features["mcolor"] = "#[pick("7F", "FF")][pick("7F", "FF")][pick("7F", "FF")]"
+			user.dna.features[FEATURE_MUTANT_COLOR] = "#[pick("7F", "FF")][pick("7F", "FF")][pick("7F", "FF")]"
-			user.dna.update_uf_block(DNA_MUTANT_COLOR_BLOCK)
+			user.dna.update_uf_block(FEATURE_MUTANT_COLOR)
 			user.updateappearance(mutcolor_update=1)
 			species.update_glow(user)
 			to_chat(user, span_notice("You feel different..."))

code/modules/surgery/bodyparts/_bodyparts.dm

@@ -982,7 +982,7 @@
 		if(owner_species.fixed_mut_color)
 			species_color = owner_species.fixed_mut_color
 		else
-			species_color = human_owner.dna.features["mcolor"]
+			species_color = human_owner.dna.features[FEATURE_MUTANT_COLOR]
 	else
 		skin_tone = ""
 		species_color = ""

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

@@ -10,7 +10,7 @@ Unlike normal organs, we're actually inside a persons limbs at all times
 	/// The savefile_key of the preference this relates to. Used for the preferences UI.
 	var/preference
 	///With what DNA block do we mutate in mutate_feature() ? For genetics
-	var/dna_block
+	var/datum/dna_block/dna_block
 
 	///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 its icon with
@@ -75,7 +75,8 @@ Unlike normal organs, we're actually inside a persons limbs at all times
 
 	var/list/feature_list = bodypart_overlay.get_global_feature_list()
 
-	bodypart_overlay.set_appearance_from_name(feature_list[deconstruct_block(get_uni_feature_block(features, dna_block), feature_list.len)])
+	var/datum/dna_block/feature/feature_block = GLOB.dna_feature_blocks[dna_block]
+	bodypart_overlay.set_appearance_from_name(feature_list[deconstruct_block(feature_block.get_block(features), feature_list.len)])
 
 ///If you need to change an external_organ for simple one-offs, use this. Pass the accessory type : /datum/accessory/something
 /obj/item/organ/proc/simple_change_sprite(accessory_type)
@@ -109,7 +110,7 @@ Unlike normal organs, we're actually inside a persons limbs at all times
 	slot = ORGAN_SLOT_EXTERNAL_HORNS
 
 	preference = "feature_lizard_horns"
-	dna_block = DNA_HORNS_BLOCK
+	dna_block = /datum/dna_block/feature/horn
 	restyle_flags = EXTERNAL_RESTYLE_ENAMEL
 
 	bodypart_overlay = /datum/bodypart_overlay/mutant/horns
@@ -118,7 +119,7 @@ Unlike normal organs, we're actually inside a persons limbs at all times
 
 /datum/bodypart_overlay/mutant/horns
 	layers = EXTERNAL_ADJACENT
-	feature_key = "horns"
+	feature_key = FEATURE_HORNS
 	dyable = TRUE
 
 /datum/bodypart_overlay/mutant/horns/can_draw_on_bodypart(obj/item/bodypart/bodypart_owner)
@@ -142,7 +143,7 @@ Unlike normal organs, we're actually inside a persons limbs at all times
 	slot = ORGAN_SLOT_EXTERNAL_FRILLS
 
 	preference = "feature_lizard_frills"
-	dna_block = DNA_FRILLS_BLOCK
+	dna_block = /datum/dna_block/feature/frill
 	restyle_flags = EXTERNAL_RESTYLE_FLESH
 
 	bodypart_overlay = /datum/bodypart_overlay/mutant/frills
@@ -151,7 +152,7 @@ Unlike normal organs, we're actually inside a persons limbs at all times
 
 /datum/bodypart_overlay/mutant/frills
 	layers = EXTERNAL_ADJACENT
-	feature_key = "frills"
+	feature_key = FEATURE_FRILLS
 
 /datum/bodypart_overlay/mutant/frills/can_draw_on_bodypart(obj/item/bodypart/bodypart_owner)
 	var/mob/living/carbon/human/human = bodypart_owner.owner
@@ -176,7 +177,7 @@ Unlike normal organs, we're actually inside a persons limbs at all times
 	preference = "feature_lizard_snout"
 	external_bodyshapes = BODYSHAPE_SNOUTED
 
-	dna_block = DNA_SNOUT_BLOCK
+	dna_block = /datum/dna_block/feature/snout
 	restyle_flags = EXTERNAL_RESTYLE_FLESH
 
 	bodypart_overlay = /datum/bodypart_overlay/mutant/snout
@@ -185,7 +186,7 @@ Unlike normal organs, we're actually inside a persons limbs at all times
 
 /datum/bodypart_overlay/mutant/snout
 	layers = EXTERNAL_ADJACENT
-	feature_key = "snout"
+	feature_key = FEATURE_SNOUT
 
 /datum/bodypart_overlay/mutant/snout/can_draw_on_bodypart(obj/item/bodypart/bodypart_owner)
 	var/mob/living/carbon/human/human = bodypart_owner.owner
@@ -208,7 +209,7 @@ Unlike normal organs, we're actually inside a persons limbs at all times
 	slot = ORGAN_SLOT_EXTERNAL_ANTENNAE
 
 	preference = "feature_moth_antennae"
-	dna_block = DNA_MOTH_ANTENNAE_BLOCK
+	dna_block = /datum/dna_block/feature/moth_antenna
 	restyle_flags = EXTERNAL_RESTYLE_FLESH
 
 	bodypart_overlay = /datum/bodypart_overlay/mutant/antennae
@@ -262,7 +263,7 @@ Unlike normal organs, we're actually inside a persons limbs at all times
 ///Moth antennae datum, with full burning functionality
 /datum/bodypart_overlay/mutant/antennae
 	layers = EXTERNAL_FRONT | EXTERNAL_BEHIND
-	feature_key = "moth_antennae"
+	feature_key = FEATURE_MOTH_ANTENNAE
 	dyable = TRUE
 	///Accessory datum of the burn sprite
 	var/datum/sprite_accessory/burn_datum = /datum/sprite_accessory/moth_antennae/burnt_off
@@ -299,7 +300,7 @@ Unlike normal organs, we're actually inside a persons limbs at all times
 	preference = "feature_pod_hair"
 	use_mob_sprite_as_obj_sprite = TRUE
 
-	dna_block = DNA_POD_HAIR_BLOCK
+	dna_block = /datum/dna_block/feature/pod_hair
 	restyle_flags = EXTERNAL_RESTYLE_PLANT
 
 	bodypart_overlay = /datum/bodypart_overlay/mutant/pod_hair
@@ -309,7 +310,7 @@ Unlike normal organs, we're actually inside a persons limbs at all times
 ///Podperson bodypart overlay, with special coloring functionality to render the flowers in the inverse color
 /datum/bodypart_overlay/mutant/pod_hair
 	layers = EXTERNAL_FRONT|EXTERNAL_ADJACENT
-	feature_key = "pod_hair"
+	feature_key = FEATURE_POD_HAIR
 	dyable = TRUE
 
 	///This layer will be colored differently than the rest of the organ. So we can get differently colored flowers or something

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

@@ -9,7 +9,7 @@
 
 	preference = "feature_lizard_spines"
 
-	dna_block = DNA_SPINES_BLOCK
+	dna_block = /datum/dna_block/feature/spine
 	restyle_flags = EXTERNAL_RESTYLE_FLESH
 
 	bodypart_overlay = /datum/bodypart_overlay/mutant/spines
@@ -31,7 +31,7 @@
 ///Bodypart overlay for spines
 /datum/bodypart_overlay/mutant/spines
 	layers = EXTERNAL_ADJACENT|EXTERNAL_BEHIND
-	feature_key = "spines"
+	feature_key = FEATURE_SPINES
 	dyable = TRUE
 
 /datum/bodypart_overlay/mutant/spines/get_global_feature_list()

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

@@ -7,7 +7,7 @@
 	zone = BODY_ZONE_PRECISE_GROIN
 	slot = ORGAN_SLOT_EXTERNAL_TAIL
 
-	dna_block = DNA_TAIL_BLOCK
+	dna_block = /datum/dna_block/feature/tail
 	restyle_flags = EXTERNAL_RESTYLE_FLESH
 
 	// defaults to cat, but the parent type shouldn't be created regardless
@@ -65,7 +65,7 @@
 
 	tail_spines_overlay = new
 	tail_spines_overlay.tail_spine_key = tail_spine_key
-	var/feature_name = bodypart.owner.dna.features["spines"] //tail spines don't live in DNA, but share feature names with regular spines
+	var/feature_name = bodypart.owner.dna.features[FEATURE_SPINES] //tail spines don't live in DNA, but share feature names with regular spines
 	tail_spines_overlay.set_appearance_from_name(feature_name)
 	bodypart.add_bodypart_overlay(tail_spines_overlay)
 
@@ -169,7 +169,7 @@
 
 ///Cat tail bodypart overlay
 /datum/bodypart_overlay/mutant/tail/cat
-	feature_key = "tail_cat"
+	feature_key = FEATURE_TAIL
 	color_source = ORGAN_COLOR_HAIR
 
 /datum/bodypart_overlay/mutant/tail/cat/get_global_feature_list()
@@ -185,7 +185,7 @@
 ///Monkey tail bodypart overlay
 /datum/bodypart_overlay/mutant/tail/monkey
 	color_source = NONE
-	feature_key = "tail_monkey"
+	feature_key = FEATURE_TAIL_MONKEY
 
 /datum/bodypart_overlay/mutant/tail/monkey/get_global_feature_list()
 	return SSaccessories.tails_list_monkey
@@ -228,7 +228,7 @@
 ///Alien tail bodypart overlay
 /datum/bodypart_overlay/mutant/tail/xeno
 	color_source = NONE
-	feature_key = "tail_xeno"
+	feature_key = FEATURE_TAIL_XENO
 	imprint_on_next_insertion = FALSE
 	/// We don't want to bother writing this in DNA, just use this appearance
 	var/default_appearance = "Xeno"
@@ -254,11 +254,11 @@
 	bodypart_overlay = /datum/bodypart_overlay/mutant/tail/lizard
 
 	wag_flags = WAG_ABLE
-	dna_block = DNA_LIZARD_TAIL_BLOCK
+	dna_block = /datum/dna_block/feature/tail_lizard
 
 ///Lizard tail bodypart overlay datum
 /datum/bodypart_overlay/mutant/tail/lizard
-	feature_key = "tail_lizard"
+	feature_key = FEATURE_TAIL_LIZARD
 
 /datum/bodypart_overlay/mutant/tail/lizard/get_global_feature_list()
 	return SSaccessories.tails_list_lizard
@@ -270,7 +270,7 @@
 ///Bodypart overlay for tail spines. Handled by the tail - has no actual organ associated.
 /datum/bodypart_overlay/mutant/tail_spines
 	layers = EXTERNAL_ADJACENT|EXTERNAL_BEHIND
-	feature_key = "tailspines"
+	feature_key = FEATURE_TAILSPINES
 	///Spines wag when the tail does
 	var/wagging = FALSE
 	/// Key for tail spine states, depends on the shape of the tail. Defined in the tail sprite datum.

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

@@ -7,7 +7,7 @@
 
 	preference = "feature_moth_wings"
 
-	dna_block = DNA_MOTH_WINGS_BLOCK
+	dna_block = /datum/dna_block/feature/moth_wing
 
 	bodypart_overlay = /datum/bodypart_overlay/mutant/wings/moth
 	restyle_flags = EXTERNAL_RESTYLE_FLESH
@@ -101,7 +101,7 @@
 
 ///Moth wing bodypart overlay, including burn functionality!
 /datum/bodypart_overlay/mutant/wings/moth
-	feature_key = "moth_wings"
+	feature_key = FEATURE_MOTH_WINGS
 	layers = EXTERNAL_BEHIND | EXTERNAL_FRONT
 	///Accessory datum of the burn sprite
 	var/datum/sprite_accessory/burn_datum = /datum/sprite_accessory/moth_wings/burnt_off

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

@@ -22,7 +22,7 @@
 ///Bodypart overlay of default wings. Does not have any wing functionality
 /datum/bodypart_overlay/mutant/wings
 	layers = ALL_EXTERNAL_OVERLAYS
-	feature_key = "wings"
+	feature_key = FEATURE_WINGS
 
 /datum/bodypart_overlay/mutant/wings/can_draw_on_bodypart(obj/item/bodypart/bodypart_owner)
 	var/mob/living/carbon/human/human = bodypart_owner.owner

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

@@ -160,7 +160,7 @@
 	preference = "feature_human_ears"
 	restyle_flags = EXTERNAL_RESTYLE_FLESH
 
-	dna_block = DNA_EARS_BLOCK
+	dna_block = /datum/dna_block/feature/ears
 
 	bodypart_overlay = /datum/bodypart_overlay/mutant/cat_ears
 
@@ -168,7 +168,7 @@
 /datum/bodypart_overlay/mutant/cat_ears
 	layers = EXTERNAL_FRONT | EXTERNAL_BEHIND
 	color_source = ORGAN_COLOR_HAIR
-	feature_key = "ears"
+	feature_key = FEATURE_EARS
 	dyable = TRUE
 
 	/// Layer upon which we add the inner ears overlay

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

@@ -103,7 +103,7 @@
 			var/mob/living/carbon/human/human = carbon
 			if(human.dna?.species)
 				//fixed_mut_color is also ethereal color (for some reason)
-				carbon.flash_lighting_fx(5, 7, human.dna.species.fixed_mut_color ? human.dna.species.fixed_mut_color : human.dna.features["mcolor"])
+				carbon.flash_lighting_fx(5, 7, human.dna.species.fixed_mut_color ? human.dna.species.fixed_mut_color : human.dna.features[FEATURE_MUTANT_COLOR])
 
 		playsound(carbon, 'sound/effects/magic/lightningshock.ogg', 100, TRUE, extrarange = 5)
 		carbon.cut_overlay(overcharge)

code/modules/unit_tests/changeling.dm

@@ -26,7 +26,7 @@
 	TEST_ASSERT_EQUAL(victim.real_name, ling_name, "Victim real name did not change on being transformation stung.")
 	TEST_ASSERT_EQUAL(victim.name, ling_name, "Victim name did not change on being transformation stung.")
 	TEST_ASSERT_EQUAL(victim.dna.species.type, ling.dna.species.type, "Victim species did not change on being transformation stung.")
-	TEST_ASSERT_EQUAL(victim.dna.features["mcolor"], ling.dna.features["mcolor"], "Victim mcolor did not change on being transformation stung.")
+	TEST_ASSERT_EQUAL(victim.dna.features[FEATURE_MUTANT_COLOR], ling.dna.features[FEATURE_MUTANT_COLOR], "Victim mcolor did not change on being transformation stung.")
 	// Check they actually look the same
 	add_to_screenshot(ling, victim)
 
@@ -37,7 +37,7 @@
 	TEST_ASSERT_EQUAL(victim.name, base_victim_name, "Victim name did not change back after transformation sting expired.")
 	TEST_ASSERT_EQUAL(victim.real_name, base_victim_name, "Victim real name did not change back after transformation sting expired.")
 	TEST_ASSERT_NOTEQUAL(victim.dna.species.type, ling.dna.species.type, "Victim species did not change back after transformation sting expired.")
-	TEST_ASSERT_NOTEQUAL(victim.dna.features["mcolor"], ling.dna.features["mcolor"], "Victim mcolor did not reset after transformation sting expired.")
+	TEST_ASSERT_NOTEQUAL(victim.dna.features[FEATURE_MUTANT_COLOR], ling.dna.features[FEATURE_MUTANT_COLOR], "Victim mcolor did not reset after transformation sting expired.")
 	// Check they actually look different again
 	add_to_screenshot(ling, victim, both_species = TRUE)
 
@@ -74,17 +74,16 @@
 	// Because we use two consistent humans, we need to change some of the features to know they're actually updating to new values.
 	// The more DNA features and random things we change, the more likely we are to catch something not updating correctly.
 	// Yeah guess who/what this is, I dare you.
-	ling.dna.features["mcolor"] = "#886600"
+	ling.dna.features[FEATURE_MUTANT_COLOR] = "#886600"
-	ling.dna.features["tail_lizard"] = "Smooth"
+	ling.dna.features[FEATURE_TAIL_LIZARD] = "Smooth"
-	ling.dna.features["snout"] = "Sharp + Light"
+	ling.dna.features[FEATURE_SNOUT] = "Sharp + Light"
-	ling.dna.features["horns"] = "Curled"
+	ling.dna.features[FEATURE_HORNS] = "Curled"
-	ling.dna.features["frills"] = "Short"
+	ling.dna.features[FEATURE_FRILLS] = "Short"
-	ling.dna.features["spines"] = "Long + Membrane"
+	ling.dna.features[FEATURE_SPINES] = "Long + Membrane"
-	ling.dna.features["lizard_markings"] = "Light Belly"
+	ling.dna.features[FEATURE_LIZARD_MARKINGS] = "Light Belly"
-	ling.dna.features["legs"] = DIGITIGRADE_LEGS
+	ling.dna.features[FEATURE_LEGS] = DIGITIGRADE_LEGS
 	ling.set_eye_color(COLOR_WHITE)
-	ling.dna.update_ui_block(DNA_EYE_COLOR_LEFT_BLOCK)
+	ling.dna.update_ui_block(/datum/dna_block/identity/eye_colors)
-	ling.dna.update_ui_block(DNA_EYE_COLOR_RIGHT_BLOCK)
 	ling.set_species(/datum/species/lizard)
 
 	ling.real_name = ling_name

code/modules/unit_tests/screenshot_humanoids.dm

@@ -6,12 +6,12 @@
 
 	// Test lizards as their own thing so we can get more coverage on their features
 	var/mob/living/carbon/human/lizard = allocate(/mob/living/carbon/human/dummy/consistent)
-	lizard.dna.features["mcolor"] = "#099"
+	lizard.dna.features[FEATURE_MUTANT_COLOR] = "#099"
-	lizard.dna.features["tail_lizard"] = "Light Tiger"
+	lizard.dna.features[FEATURE_TAIL_LIZARD] = "Light Tiger"
-	lizard.dna.features["snout"] = "Sharp + Light"
+	lizard.dna.features[FEATURE_SNOUT] = "Sharp + Light"
-	lizard.dna.features["horns"] = "Simple"
+	lizard.dna.features[FEATURE_HORNS] = "Simple"
-	lizard.dna.features["frills"] = "Aquatic"
+	lizard.dna.features[FEATURE_FRILLS] = "Aquatic"
-	lizard.dna.features["legs"] = "Normal Legs"
+	lizard.dna.features[FEATURE_LEGS] = "Normal Legs"
 	lizard.set_species(/datum/species/lizard)
 	lizard.equipOutfit(/datum/outfit/job/engineer)
 	test_screenshot("[/datum/species/lizard]", get_flat_icon_for_all_directions(lizard))
@@ -24,9 +24,9 @@
 
 	// let me have this
 	var/mob/living/carbon/human/moth = allocate(/mob/living/carbon/human/dummy/consistent)
-	moth.dna.features["moth_antennae"] = "Firewatch"
+	moth.dna.features[FEATURE_MOTH_ANTENNAE] = "Firewatch"
-	moth.dna.features["moth_markings"] = "None"
+	moth.dna.features[FEATURE_MOTH_MARKINGS] = "None"
-	moth.dna.features["moth_wings"] = "Firewatch"
+	moth.dna.features[FEATURE_MOTH_WINGS] = "Firewatch"
 	moth.set_species(/datum/species/moth)
 	moth.equipOutfit(/datum/outfit/job/cmo, visuals_only = TRUE)
 	test_screenshot("[/datum/species/moth]", get_flat_icon_for_all_directions(moth))
@@ -35,7 +35,7 @@
 	// More in depth test for slimes since they have a lot going on
 	for (var/datum/species/slime_type as anything in typesof(/datum/species/jelly))
 		var/mob/living/carbon/human/slime = allocate(/mob/living/carbon/human/dummy/consistent)
-		slime.dna.features["mcolor"] = COLOR_PINK
+		slime.dna.features[FEATURE_MUTANT_COLOR] = COLOR_PINK
 		slime.hairstyle = "Bob Hair 2"
 		slime.hair_color = COLOR_RED // Should be forced to pink
 		slime.set_species(slime_type)

code/modules/unit_tests/species_change_clothing.dm

@@ -7,7 +7,7 @@
 	var/mob/living/carbon/human/morphing_human = allocate(/mob/living/carbon/human/dummy/consistent)
 
 	morphing_human.equipOutfit(/datum/outfit/job/assistant/consistent)
-	morphing_human.dna.features["legs"] = DIGITIGRADE_LEGS //you WILL have digitigrade legs
+	morphing_human.dna.features[FEATURE_LEGS] = DIGITIGRADE_LEGS //you WILL have digitigrade legs
 
 	var/obj/item/human_shoes = morphing_human.get_item_by_slot(ITEM_SLOT_FEET)
 	human_shoes.supports_variations_flags = NONE //do not fit lizards at all costs.

tgstation.dme

@@ -812,7 +812,6 @@
 #include "code\datums\dash_weapon.dm"
 #include "code\datums\datum.dm"
 #include "code\datums\datumvars.dm"
-#include "code\datums\dna.dm"
 #include "code\datums\dog_fashion.dm"
 #include "code\datums\drift_handler.dm"
 #include "code\datums\ductnet.dm"
@@ -1452,6 +1451,10 @@
 #include "code\datums\diseases\floor_diseases\carpellosis.dm"
 #include "code\datums\diseases\floor_diseases\gastritium.dm"
 #include "code\datums\diseases\floor_diseases\nebula_nausea.dm"
+#include "code\datums\dna\dna.dm"
+#include "code\datums\dna\dna_block.dm"
+#include "code\datums\dna\blocks\dna_features_block.dm"
+#include "code\datums\dna\blocks\dna_identity_block.dm"
 #include "code\datums\elements\_element.dm"
 #include "code\datums\elements\ai_control_examine.dm"
 #include "code\datums\elements\ai_flee_while_injured.dm"