Metallo is a supervillain appearing in American comic books published by DC Comics, commonly as an adversary of Superman. He is usually depicted as a cyborg with a kryptonite power source in his heart, which he uses as a weapon against Superman. In 2009, Metallo was ranked as IGN's 52nd-greatest comic book villain of all time.

Superman: Secret Origin is a six-issue monthly American comic book limited series published by DC Comics. The series was written by Geoff Johns and illustrated by Gary Frank, featuring the superhero Superman. The story featured the "definitive" origin of Superman for the modern, post-Infinite Crisis DC Universe continuity, starting with Clark Kent in his pre-teens as Superboy. Within the series he goes on to meet a young Lex Luthor and the Legion of Super-Heroes in Smallville, Kansas, and soon heads to Metropolis where a young adult Clark debuts as Superman.