there are three types of chao: Normal, Dark and hero chao.
Normal chao are blue and yellow. they can evolve if you stroke them with both a hero character and a dark character to make a balance instead of like sonic (or whoever) spending too much time over her (chao have no sex but i think they are all girls). they evolve over time if you leave them blue.
hero chao can be obtained by stroking the baby chao with a hero character. do this untill she is white with a blue ball over her head,
which will turn into a halo.
dark chao can be obtained by stroking or throwing( I'm highly against it but you can do that if you want) with a dark character.
hint: try doing this with a white or shiny white chao. She can look pretty cool!
