Get any color chao and then give him all the animals you 
get, if you are lucky he will be changing color, take 
very good care of him (meaning dont hit him) and he 
will sit down after you give him alot of animals. When 
he sits down he will get into a shape, the shape he does 
when he is going to run away, dont worry if you haven't 
hit him. When he gets out of the egg he will be an adult 
chao and ready to mate.