Who is metal guy on xmen?

The metal man on X-Men is Colossus. Piotr Nikolaievitch Rasputin, also known as Colossus, is a fictional character appearing in American comic books published by Marvel Comics and is a founding member of the X-Men. Created by writer Len Wein and artist Dave Cockrum, the character first appeared in Giant-Size X-Men #1 (May 1975).