Somthing ain't right about the Butterfree, Mesprit and Glaceon Chao... those Pokemon parts seem a bit big for a chao...
And to answer the question that's been asked:
Chao are those little A-Life things from the Sonic games (I think they made thier first appearance in NiGHTs, though.) (They can be raised in Sonic Adventure, Sonic Adventure 2, Sonic Advance, Sonic Advance 2, & Sonic Pinball Party. They're also important in Sonic Advance 3 and Sonic Chronicles. and they can be seen in Sonic Heroes, Shadow The Hedgehog, and the Sonic X anime.)
BTW, it's "Chao" in both Singular and Pural form. (and incase you're wonding, it's pronounced like Chow)
And Azumi, I think that red-and-yellow egg on the right is supposed to be Magby or something.