Metallo is a fictional character from the DC Comics universe, primarily known as an adversary of Superman. He is a cyborg, originally a human named John Corben, who was transformed into a powerful being with a body made of metal. This transformation grants him superhuman strength and durability, making him a formidable opponent for the Man of Steel. In addition to his physical enhancements, Metallo possesses a heart powered by a kryptonite core, which is a significant weakness for Superman. This connection to kryptonite allows Metallo to exploit Superman's vulnerabilities, making their confrontations particularly intense and dangerous.