Sonic Adventure 2 Battle?
I had this handicapped everything-maxed chao. He was also shiny, but normal at the same time :O
He was pretty damn fast in races, and usually 1-hit everything in those fighting competitions. Only problem is, one of the Chao I used in the breeding program had a bunch of terrible traits (lazy, never stops eating or sleeping, batstuff handicapped, etc.) and so the end result retained a few of those traits.
All his stats were 3000+ I think, there was probably a way to go higher then that but I dunno except for cheating maybe. All his stats were also S rank.
Couldn't play Sonic DX after playing SA2B