Metallo

Metallo is a prominent enemy of Superman and a supervillain from DC comics - he is one of the Man Of Steel's more dangerous opponents due to the fact he has transformed himself into a cyborg that is powered by green kryponite - a substance that is deadly to Superman in large doses and severely weakens him whenever he becomes exposed to it.

Metallo started his life as a simple criminal but became a much more powerful villain after having his body upgraded