Beyblade

When you first see Goki reflecting on the current match between Kane and Salima, he suddenly has blue hair and eyebrows like Kane!

And since when have legal specifications mattered? Draciel used to have about five or six ball bearings in his base, Driger had a clutch system in his and Galeon had a spike for a spin tip, plus the Bladebreakers all use magnetic spin gears. Surely, Tyson's modifications shouldn't be that much of a moral problem.