There are seven groups of animals, and each group has three animals. You can give animals to your Chao to make it stronger and to give it different personalities and looks. When you give a Chao an animal, it will embrace it, and attain its appearance, abilities, and behaviour. The animal will disappear after you give it to a Chao.

The animals are found hidden throughout the levels, usually in locked cages that you must destroy or in small pipes scattered around the stages (that you have to whistle at). You can also find them in the robots created by Dr. Eggman such as the bomb-throwing monkeys, or the robots that look like E-102 Gamma.

The four common animal colours — yellow, purple, green, and red — all raise the primary stats: swim, fly, run, and power, respectively, and may decrease other stats slightly in the process. The other three colour groups command control over the other stats. Blue, gold and black animals will not decrease any stats when given to the Chao. On the Dreamcast, luck and intelligence cannot be raised with animals.

The animals, their groups, and their effects
Group Info Animal Info Stat Bar Changes
Type Colour Icon Name Swim Fly Run Power Effect
Swim Yellow Penguin Penguin +3.6 +1.2 +0.8 -2.4 Learnt behaviour: Chao slides on its belly.
Otter Otter +4.4 -0.4 +0.8 -1.6 Learnt behaviour: Chao performs the backstroke when swimming.
Seal Seal +4.0 -1.6 0 +0.8 Learnt behaviour: Chao rolls around.
Fly Purple Condor Condor +2 +6 -2.4 +1.6 Learnt behaviour: Chao flaps about.
Parrot Parrot 0 +4.8 -2 +0.4 Learnt behaviour: Chao sings.
Peacock Peacock +1.2 +4.8 -1.6 -1.2 Learnt behaviour: Chao struts about.
Run Green Warthog Warthog -0.4 -1.2 +3.2 +1.6 Learnt behaviour: Chao dashes.
Cheetah Cheetah -0.8 -0.8 +4 +0.8 Learnt behaviour: Chao licks its face.
Rabbit Rabbit 0 +0.8 +4 -1.6 Learnt behaviour: Chao hops about.
Power Red Bear Bear +0.8 -1.6 +0.4 +3.6 Learnt behaviour: Chao roars.
Gorilla Gorilla -0.4 -0.8 +0.4 +4 Learnt behaviour: Chao beats on its chest.
Tiger Tiger -0.8 -1.6 +2 +3.6 Learnt behaviour: Chao sharpens its nails.
Miscellaneous Blue Raccoon Raccoon +2 +1.6 +0.4 +0.8 Learnt behaviour: Chao spins around.
Sheep Sheep +0.8 +0.8 +1.6 +1.6 Learnt behaviour: Chao performs forward somersaults.
Skunk Skunk +0.8 +1.2 +1.6 +1.2 Learnt behaviour: Chao farts.
Mythical Gold Dragon Dragon +2 +0.4 +0.8 +3.2 Learnt behaviour: Chao breathes fire.
Phoenix Phoenix +1.2 +3.2 +0.4 +1.6 Learnt behaviour: Chao wags its tail.
Unicorn Unicorn +1.6 +1.2 +3.6 0 Learnt behaviour: Chao bucks its feet.
Ghost Black Bat Bat +0.8 +4 +0.8 +0.8 Appearance: Makes the Chao's legs disappear.
Half Fish Half Fish +3.2 0 +0.8 +2.4 Appearance: Turns the Chao's emotion ball into a flame.
Skeleton Dog Skeleton Dog +0.8 +0.8 +3.2 +1.6 Appearance: Removes animal parts from the Chao, and allows hats to be worn.