First appearance: Iron Man #55 (1973)
Created by: Jim Starlin
Most villainous act: Attempting to destroy the universe just to impress a girl.
No villain is as simultaneously terrifying and pathetic as Thanos. On one hand, the Mad Titan is one of the most powerful beings in the universe, capable of wielding the all-powerful Infinity Gauntlet for his own gain. But the main reason why he craves destruction is because he wants to impress Mistress Death, who he has a schoolboy crush on.
This is the type of romantic drama more suited for Archie and Veronica, but it plays out on a cosmic scale. It's a brilliant premise, though, and it just goes to prove Freud right, that everything eventually boils down to sex. Lady problems aside, Thanos is a tyrant of pure destruction and hatred who is more than worthy of going toe-to-toe with Marvel’s heavyweights. We can't wait to see him show up in an Avengers sequel. Hopefully his next role will include more than just a smirk.