Galactus

Although he’s not actually an outright villain by nature – he’s a cosmic force whose existence is essential to the balance of the universe – Galactus is understandably perceived as a threat, due to the fact that he eats planets and, as such, is often considered to be evil.

In fact, when most people think of powerful comic book villains, he’s one of the first characters who springs to mind. In order to obtain sustenance, he threatens entire civilizations, and heroes often have to step in to prevent him from doing so.

But such is the power of Marvel’s Devourer of Worlds that barely anyone is capable of stopping him. In fact, only Reed Richards’ threat to use the Ultimate Nullifier – a device that could destroy reality itself – has ever really put a stop to Galactus’ going about his planet-eating ways. The fact that he is also a genius with powerful equipment of his own makes him even more dangerous than he otherwise is – he’s a genuine universal threat.