10 Most Underrated Superman Villains

John Corben is known as The Man with the Kryptonite Heart because... well... it's pretty self-explanatory. But since that's a bit of a mouthful, Corben's also known as Metallo. With his cybernetic body, he can control machines, heal from any injury, and modify his limbs into weapons.

Because of his near-indestructible body, Metallo is a dangerous foe to anyone. But because he is powered by kryptonite, he is one of Superman's deadliest rivals. According to the spit-curled superhero, being exposed to the green metal feels like his blood has been replaced with battery acid. That's what Superman feels any time he gets near this guy.

If you thought the Man of Tomorrow could fight Metallo from a distance, it's not that simple. The nefarious android can shoot kryptonite from his eyes or heart, blasting Superman long before he gets near him. He sometimes uses multiple forms of kryptonite (red, green, blue, yellow) so he has several ways to immobilise Superman.

Metallo is yet to make it to the big screen, but Malcolm McDowell voiced the character in the superb Superman: The Animated Series, where he was a recurring antagonist.