Squirrel
Axolotl
Chameleon
Frogling
Squirrels are known to be, well, squirrley, but these creatures are more on the chaotic side.
Acorn Holder: Just like foxes, squirrels have a big enough mouth to store many things. Works just like the shulker and fox inventory. You gain 9 slots of inventory that stay even after death.
Speedy: You gain permanent speed 1 due to your small and nimble size.
Tree Climber: Your claws allow you to climb up the sides of blocks. Works like the spider climbing.
Adorable Size: You are one block tall and only have 7 hearts.
Vegetarian: You can only eat plants and fruits.
Small Arms: Due to your small arms, you are unable to hold a shield correctly.
Little Menace: Villagers are afraid of you and iron golemns will attack on sight. (I don't know if this works)
Native to Lake Texcoco in the mountains of central Mexico in real life, these guys are critically endangered. They have captured the world with their adorableness though!
Cave Vision: You gain night vision in the dark.
Powerful Swimmer: You swim very well!
Play Dead: When you use your primary power, you gain regeneration for 10 seconds, but you're immobilized until the regeneration is gone. Cooldown for 30 seconds.
Tiny Boi: You are only a block tall and only have 5 hearts of health.
Gills: Your feathery gills allow you to breathe underwater, but not on land.
These lizards are able to change their scales to match the colors of their environment. Their cold blood can be a hinderance at times, but can be a plus in certain hellish dimensions.
Camouflage: When you crouch, you turn invisible after a bit of time.
Scales: You have resistance 2 due to your rough and scaly skin.
Cold Blooded: You gain speed while in the nether, but slowness in a cold biome.
Small: You are only 1 and a half blocks tall.
Smelly: Chameleons don't smell great at all, so villagers run away from you (Chameleons do actually smell in real life!).
Bad Immune System: Due to your terrible immune system, all damage potion effects do more damage (Chameleons have a terrible immune system).
They go boing!
Bouncy: Because you are a frog, you gain jump boost II
Moist Skin: Your moist skin is perfectly suited for underwater environments, allowing you to breathe underwater.
Webbed Hands: You can swim well, but you have constant weakness due to your hands being webbed and more suited for swimming than combat.
Smol: You are only 1 block tall and only have 5 hearts.
Low Energy: Since most of your energy is used by jumping, you are slightly slower than the average human.
Carnivore: You can only eat meat.