Once it evolves, ascending stairs should appear at the main Chao lobby leading to the Hero Garden. Continually feed and train your Hero Chao and it should evolve (creates a tear-shaped 'cocoon'). To unlock the Chao Hero Garden, you must raise a Hero Chao with one of the three Hero characters.

In order to unlock the Kart game, in the Hero Side story, complete the Tails driving quest and in Dark Side story, successfully finish the Rouge chase mission. You'll be able to fight each boss from either Hero or Dark side. To unlock the Boss Attack mode, complete either Hero or Dark side story modes. On a side note, feeding your chao several sea monsters will return it to its normal form (as if you had only fed it chaos drives). Sometimes this won't take it's effect until it has been fed several sea monsters. If you feed your leg-less chao a sea monster, it might grow its legs back. They resemble the little green guy dancing around in the black market. To get them feet once more, use sea monsters. Pyramid cave level) chances are high that your chao will lose its feet and grow a little genie-like tail. Message: If you feed your chao a bat, (ex.