As you see in my Character Chao (Unofficial) section, I give you formulas to understand how to make them. I'll label it something like: D:P:P
...To interpret that, look at the first letter, they describe the alignment of the chao. The following (H, N, or D) means:
H: make sure your chao is of the hero alignment when goes into its cocoon
N: make sure your chao is of the neutral alignment when goes into its cocoon
D: make sure your chao is of the dark alignment when goes into its cocoon
The next letter signifies what you need to give your baby chao (before it cocoons). The following (Y, R, P, or F) means:
Y: swimming Chao: yellow chaos drives and/or animals should be given in abundance to your chao
R: running Chao: green chaos drives and/or animals should be given in abundance to your chao
P: power Chao: red chaos drives and/or animals should be given in abundance to your chao
F: flying Chao: purple chaos drives and/or animals should be given in abundance to your chao
The same goes for the last letter symbol in the formula. Only difference is that they can only be given to an adult chao who already went through its cocoon. Changes are very gradual.. The following (Y, R, P, or F) means:
Y: swimming Chao: yellow chaos drives and/or animals should be given in abundance to your chao
R: running Chao: green chaos drives and/or animals should be given in abundance to your chao
P: power Chao: red chaos drives and/or animals should be given in abundance to your chao
F: flying Chao: purple chaos drives and/or animals should be given in abundance to your chao