Rename the listed mobs/pets with the following name tags names and their texture will change:

Cat:
-"Jellie" - Astronaut Cat
-"Alice" - Horned Monster Cat

Wolf:
-"DMT" - One-Eyed Rainbow Dog
-"Doge" - Shiba Inu
-"Wireframe" - Outline-Only Dog
-"Grizzly" - Black-Eyed Red Dog
-"Kimo" - Slit-Eyed Snow Dog
-"Mima" - Pink Snow Dog
-"Grim" - Skeleton Dog
-"Duck" - Goofy Looking Duck-Dog(?)
-"Lazarus" - Zombie Dog

Horse:
-"Krieg" - Red Zombie Horse
-"Wireframe" - Outline-Only Horse

Chicken:
-"duck" - White Duck
-"Zam" - Same as "duck"

Creeper:
-"Jello" - Eyepatch Creeper

Enderman:
-"Jim-Bob" - Old Farmer Enderman

Slime:
-"Jello" - Eyepatch Slime

Zombie:
-"Prisoner" - Prisoner Uniform Zombie
-"Finn" - Zombie wearing Adventurer Uniform

Rename the listed armor pieces in an anvil and their texture will change:

Masks:
Works on any of these helmets: Gold, Iron, Chainmail, Diamond

-"Angry Mask" - Angry Face
-"Smile Mask" - Happy Face
-"Emoji Mask" - Crying Laughing Emoji
-"Irony Mask" - This emoticon: ":^)"
-"NPC Mask" - Grey unexcited face
-"Purple Guy Mask" - Mask of a creepy Purple Guy

Yeezys:
Rename any type of boots (except leather) to something with "yeezy" in the name.
Example: Diamond Boots called "My fresh Yeezys"

-Chainmail Yeezys: Checkered Yeezys, Orange and Blue Details
-Iron Yeezys: Grey Yeezy, Red Detail
-Gold Yeezys: Gold Yeezy, Light Green Detail
-Diamond Yeezys: Turquoise Yeezy, Light Blue Detail
-Netherite Yeezys: Black Yeezy, Dark Grey Detail

Crowns:
Rename a golden or netherite helmet to something with "crown" in the name.
Example: Golden Helmet called "Herobrine's Crown"

-Gold Crown: Golden Crown
-Netherite Crown: Purple Crown

Miscellaneous:

-Diamond Helmet: "Glasses" - Cool Glasses with Diamond for Lenses

Rename an elytra in an anvil and it's texture will change:

Gliders:
Triangular Gliders with material-based textures:

-"Iron Glider"
-"Diamond Glider"
-"Netherite Glider"

Miscellaneous:

-Elytra with "trans" in it's name - Trans Pride Flag Elytra

Rename the listed items in an anvil and their texture to change:

Diamond Pickaxes:

-"Bigaxe" or "Thiccaxe" or "Thickaxe" - Thicker Pickaxe Head
-"Fortnite" - Pickaxe with a Plunger Base and a Sword Head
-"Drill" - 3D-Modeled Diamond Drill
-"Weirdaxe" - Extremely Thin Pickaxe

Diamond Swords:

-"Chickenwing" - Just a Chickenwing
-"Creeper Sword" - 3D-Modeled Creeper on a Stick
-"Dab" - Diamond Sword with Bent Parts Dabbing
-"Fork" - 3D-Modeled Diamond Fork
-"Shokata" - Blue Softdrink

Iron Swords:

-"Fork" - 3D-Modeled Iron Fork

Bows:

-"Babybow" - Smaller Bow
-"Microbow" - Even Smaller Bow

Miscellaneous:

-Paper named "IOU" - Paper with Smiley Face

Some mob texture variants have a chance to appear naturally in your world. They are only seen by your game instance and will be reset when reloading the mob/world.

-Eyepatch Creeper: 0.5% Chance
-Old Farmer Enderman: 0.5% Chance
-Eyepatch Slime: 2.5% Chance
-Prisoner Zombie: 0.25% Chance
-Adventurer Zombie: 0.25% Chance
-Duck Chicken: 4% Chance