The Official Super Smash Bros. Brawl Project (Now at Phase 2!)

[Random Talking Bush]

Nope. Snake's eyeball is just one texture (eye white and pupil on the same texture), Toon Link and Wario have multiple eye layers, but the UV mapping is the exact same for each layer.

Likewise, in contrast to Bowser, Giga Bowser's eye texture layers also use the same UV mapping, so there's no problem there, either.