Heroes aren't exempt from having mental problems. Nothing drives drama like a hero losing his or heror her marbles and turning against his allies. The power that makes them great often comes with a precarious fragility and it's that imbalance that draws us to their struggle.
Even without the superhero dynamic, the crazy cream often rises to the top to create some of the most lasting impressions. This list contains the most unstable, insane, and downright crazy characters to ever grace the pages of comic books.
First Appearance: Batman #1
The Clown Prince of Crime is so insane, he's almost sane. His steadfast commitment to chaos is so consistent, it's almost more of a philosophy than an ailment. He seems to enjoy being locked up in Arkham Asylum to the degree where it's fair to wonder if he likes being caught. His cunning betrays a vast intelligence, but at the end of the day, he's still a psychotic, sociopathic mass murderer.
Appears In: Batman: The Brave and the Bold, Batman: The Animated Series, Fight Batman Fight!, Batman: New Times, Batman: The Dark Knight Returns, + more
Also Rankedsee more on Joker
First Appearance: The Batman Adventures #12
Serving as a psychiatrist in Arkham Asylum, Harleen Quinzel was supposed to be one of the sane ones, but she fell in love with The Joker and joined him as his psychotic sidekick. This is what happens when mental professionals don't maintain boundaries.
Appears In: Batman: The Animated Series, Birds of Prey, Batman: New Times, DC Universe
#13 on The Best Comic Book Villainssee more on Harley Quinn
First Appearance: New Mutants #98
It's hard to tell if the "Merc with a Mouth" is the craziest character in the Marvel Universe or the only sane one. Deadpool has become aware that he is a comic book character. He speaks directly to the reader, and recognizes the absurdity of his Spandexed world, but barely knows his own origin as a result of Marvel's sloppy continuity.
Appears In: Deadpool, X-Men Origins: Wolverine, Hulk Vs, Marvel Universe
Powers/Abilities: Martial arts, Healing factor, Immortality, Superhuman strength, Teleportation
Also Rankedsee more on Deadpool
First Appearance: The Amazing Spider-Man #344
Anarchist Cletus Kassidy was already a serial killer who burned down the orphanage he grew up in and killed at least 20 people before bonding with an alien symbiote that gave him super powers. There's no better way to level up your serial killer XP.
Appears In: Marvel Universe
Powers/Abilities: Shapeshifting, Healing factor, Superhuman speed
#14 on The Best Comic Book Villainssee more on Carnage