10. Galactus (First appearance: The Fantastic Four (1961) No. 48)
He eats whole worlds for crying out loud! Galactus' evil comes from a constant hunger, one that his god-like, near limitless size can never fill. He doesn't just threaten civilizations, he completely ends them (and then some).
9. Sabertooth (First appearance: Iron Fist (1975) No. 14)
Occasionally “good”, but it never lasts. And he can never really make up for the murders and destruction he's caused in his long, long life. Next to Wolverine, Victor Creed has one of comics' most confusing and mixed-up histories, but his capacity for evil is a constant.
8. Doomsday (First appearance: Superman: The Man of Steel (1991) No. 18)
Talk about making an entrance … Doomsday “killed” the world's most famous superhero and has caused Superman constant trouble ever since.
7. The Red Skull (First appearance: Captain America (1941) No. 7)
Born from real-world evil, Captain America's lifetime nemesis can claim to no less than Adolph Hitler as a partner. These days, with help from the brain of Professor Xavier, the Red Skull is one of the most powerful beings on the planet.
6. The Governor (First appearance: The Walking Dead (2001) No. 27)
Watchers of AMC's hit television adaptation of Image Comics' The Walking Dead know how terrible The Governor can be, but that's nothing compared to the horrors he unleashed on Rick and company in the comics.
5. Apocalypse (First appearance: X-Factor (1986) No. 6)
Doomsday, Apocalypse … The names alone screams ‘bad guy'. An evil that's been around since the time of the Pharaohs, Apocalypse is the perfect mutant, and the perfect X-Men villain.
4. Carnage (First appearance: The Amazing Spider-Man (1963) No. 361)
Venom eventually became a “good guy”, but not the other major symbiote of the 90's. Cletus Kasady's Carnage was a darker version of Venom, a psychopath and a homicidal sadist, that always challenged Spider-Man. The symbiote has only gotten more crazy and more dangerous over time.
3. Thanos (First appearance: The Invincible Iron Man (1968) No. 55)
Thanos is all about impressing a lady — Death. How do you do that? You kill as many people and things as possible. Consider that the Mad God swings the all-powerful Infinity Gauntlet, and you have one of the most dangerous beings in the Marvel Universe.
2. Doctor Doom (First appearance: The Fantastic Four (1961) No. 5)
He wears a magical suit of armor made from his ex-girlfriend's skin. Let that sink in for a minute. Not enough for you? He's a mad-genius and dictator of a small European country, ruling with a (literal) iron fist.
1. The Joker (First appearance: Batman (1940) No. 1)
THE classic Batman villain, the sociopathic Clown Prince of Crime conjures up over 70 years of madness and evil. He's killed sidekicks, paralyzed innocents, and dedicated himself to mindless violence. There's not another villain filled with this much evil.