This texture pack will add variety to the game for all creatures. Now, each mob has several texture variations, even Steve and Alex! Optifine is required for the texture pack to work.
You can send your textures for mobs to Lugix#8626 discord and if the author thinks they are suitable, they can be added to the texture pack.
Screenshots of the Diversity of Mobs texture
Video about Variety of Mobs [1.12.2]
How to install Diversity of Mobs
Install Optifine HD (Optional but recommended)
Copy the resource pack to your .minecraft\resourcepacks folder.
Choose your desired resource pack in the game settings