Originally posted by KingD19
No, Colossus doesn't need to breathe. Not in the comics, and since it wasn't brought up in the movies, it's safe to assume they kept him close enough to his comic counterpart that it applies there as well.
I know in the comics he doesn't, or at least he's been shown to survive underwater without breathing.
But in the film, wasn't his chest moving in a breathing fashion while transformed?