Comments: A man of both enormous size and heart, he was the mutant that men feared and other mutants revered. At once a farmer, an artist, and a gentleman, he was also a brute force in battle. Born Piotr "Peter" Rasputin in Lake Baikal, Siberia, Peter first manifested his tremendous mutant ability ( he was able to transform his body tissue into an organic steel-like substance) in his adolescence. Peter later joined Professor X and the X-Men and proved to be a hero to all mutantkind.
Source: Marvel Comics - Colossus, X-Men, Excalibur, The Last Defenders