Sonic Adventure/Chao

Start raising your Chao by entering Chao Gardens. There are 3 different Chao Gardens. There are also 4 phases in the Chao's life. First is the egg phase. Its expression depends on what you decide to do with the egg. If you decide to throw it against the wall to make it hatch, or if you wait for the Chao to hatch on its own. The next phase is the baby phase. When it's done with this phase, it will go through a brief cocoon phase. It makes a shell for itself, and when its done, will come out as an adult. The shell is in the shape of an egg, and gets darker as the Chao's evolution progresses. After they come out of the cocoon, they will be fully-developed adults.

Animals
It will first start out as a young Chao, but will evolute into a grown Chao. Its physical appearance and abilities depend on what you give the Chao. You can give them animals to boost their stats in swimming, flying, running, power, and all.

Black Market
The Black Market is an exclusive to the GameCube update of the game, Sonic Adventure DX: Director's Cut. It was added after the release of Sonic Adventure 2 Battle, which had a similar shop system. It is owned and run by a Chao, and sells everything you need to raise your Chao. You must use rings to purchase anything from the Black Market.

Chao Eggs
Your Chao's color also depends on what color the egg is. A default Chao Egg gives you the original Chao color, pale blue.

Fruits
Fruits are needed to feed your Chao. The only one that is available for free is the Garden Tree Fruit, which you have to shake off of trees in the Chao Garden.

Masks
Masks can be given to your Chao to wear. After they're put on, they can't be taken off. The Chao can only take it off when it gets tired of it.