Instructions
Determine whether you want an Angel, Devil or Light Chaos Chao. For an Angel, you must raise the Chao with only hero characters. For the Devil Chao, use only Dark characters. To get the Light Chao, raise it with both Hero and Dark characters equally.
Feed your Chao fruit and give it drives to speed up its growth. If its stats are very high, it will evolve quickly.
Wait for the Chao to evolve into an adult. Treat the Chao as well as possible by petting and feeding it. If you neglect the Chao, it will not evolve.
Leave the game running for a few hours. When the Chao dies, it reincarnates, leaving behind an egg. Hatch this egg and raise the Chao again using the same method as before.
Wait for the Chao to reincarnate again. Go to the "Stage Select" menu and collect each of the 21 small animals scattered throughout the stages. This includes the legendary animals such as the unicorn and phoenix.
Give the Chao each of the animals while it is still a baby. When the Chao evolves, it turns into a Chaos Chao.