Well, when you go through a stage, there are boxes hiding around with a chao symbol on them. The first one you break, you get a key. Once you finish the stage, you can enter chao world and it becomes accessable through stage select (:
The 2nd box- animals (to feed ur chao)
the 3rd box- a mythical animal (to feed chao)
Chat with our AI personalities
You have to buy it
Sonic Advance 1, 2 and 3 (Gameboy Advance) have chao gardens which are small and not very great, but Sonic Adventure (Dreamcast), Sonic Adventure DX (GameCube), Sonic Adventure 2 (Dreamcast), Sonic Adventure 2 Battle (GameCube) all have chao gardens where you can do the most things and raise your chao the best and most effective. Sonic Adventure 2 Battle is the most convinient and shows you all you need to know about a chao, and it's a really good game to raise them in by using animals (and Chaos Drives) as a means of training them. Sonic Advance 1 and 2 can connect up to Sonic Adventure 2 Battle and Sonic Adventure DX via a Gameboy to GameCube link cable and you can exchange chao with.
Attack it. Also, it's Sonic Adventure 2 Battle.
buy it in the black market
When ignored or abused I believe