My chao went into it's pink cocoon twice but we only found 20 animals was..

Although I never got a chaos chao before the steps are pretty easy.

First let your chao go into its socond pink cocoon then give it all 21 animals.

No you don't feed it twice.

Just give the chao all 21 in its socond tansformation.

For the joker looking chao its really a neuturl flying.

Just give it al lot of flying types till about L20 or highrer with tails (i think) and no chaos dives it might mess it up.

When it evoles its wings will be huge and it's head will have some sort of joker that I can't really tell what it is.

For a chaos chao (I have 16 of them so trust me), wait for it to transform, then it will die a little while later(but it will come back if it loves you.

Let all this happen twice then the second it comes out of an egg, start giving it 1 of every animal.

I know this answer was already submitted, but I'm going to go a step further and tell you the easiest way to find them:

For an Angel:
City escape-raccoon, rabbit,skunk
Wild Canyon-sheep, cheeta, peacock, condor
Prison Lane-gorilla, unicorn
Metal Harbor-penguin
Green Forest-parrot, half-fish
Pumpkin Hill-bat, boar, skel. dog
Aquatic Mine-dragon, seal
Hidden Base-sea otter
Death Chamber-tiger
Meteor Herd-pheonix
Crazy Gadget-bear

For a Devil:
Iron Gate-gorilla, dragon
Dry Lagoon-peacock, sheep, penguin, sea otter, unicorn
Sand Ocean-bat, skel. dog
Radical Highway-cheetah, boar, raccoon, seal
Egg Quarters-half-fish
Security Hall-parrot
White Jungle-skunk
Sky Rail-bear, condor, tiger
Cosmic Wall-rabbit
Final Chase-pheonix

For a Neutral(or Light):
Just mix up who gives the animals to it (like 1/2 sonic and 1/2 shadow).

As for the joker looking chao:
For those who haven't played sonic adventure DX, that chao is the spitting image of Knights. To get it give a chao lots of condors with any dark character(the easiest is Shadow).