Batman is one of the longest-lasting characters in DC Comics, debuting over 80 years ago. This gives Batman one of the biggest rogue's galleries in comics, and his villains are arguably more famous than any other superhero's. His villains are also unique in that almost none of them have superpowers and are mostly mobsters and thieves. Those who do have powers often gain them through scientific means.
However, that does not make them less dangerous than the superpowered beings that Superman fights. These Batman villains are as dangerous, if not more so than the superpowered villains that run rampant throughout DC, and make up for what they can't do with powers by using their evil intentions.
Scarecrow
Scarecrow is Jonathan Crane, who was a well-respected professor who created a chemical that spread fear to anyone afflicted by it.
This makes Scarecrow extremely dangerous, and the fact that his toxins bring out the greatest fears of his victims, and his only goal is to drive them insane, makes him as evil as a villain can get. Scarecrow has experimented on college students, murdered his grandmother, poisoned all of Gotham City, and created the horrific Scarebeast.
Professor Pyg
Professor Pyg is one of the creepiest villains in Batman comics, and only part of it is his giant pig face mask. Professor Pyg made his debut in an infamous issue, showing up for the first time in Batman & Robin #1 by Grant Morrison and Frank Quitely in 2009.
He was a chemist, and he created a drug that mimicked Alzheimer's disease in anyone he infected. This is a horrific move in itself and cements Pyg's status as a terrible villain. He also is guilty of experimenting on victims as he tries to achieve the idea of perfection.
Black Mask
The world got to know all about Black Mask thanks to the Birds of Prey movie, with Ewan McGregor taking on the role of the Gotham City mobster. Roman Sionis is a crimelord who rules with an iron fist.
Unlike his movie version, Black Mask had his face scarred so much that it duplicated his mask. Among his evil moves was corrupting a good cop in Harvey Bullock, posing as the Dark Knight himself, and building one of the most violent criminal empires in Gotham City.
Talon
Talon was the name used by several people throughout history, and the men who use this name have helped the Court of Owls rule Gotham City behind the scenes for many years. The Talons were warriors that the Court of Owls sent out to kill the people who threatened them.
When Batman learned about the Court of Owls and took the battle to them, this is when one specific Talon rose named William Cobb and is responsible for many atrocities against the Waynes, killing many members of Bruce's family. Talon is also Dick Grayson's great grandfather and tried to turn him evil.
Bane
Bane is one of Batman's most dangerous and evil villains. He is a genius who uses the Venom serum to give him super strength. He had made Batman's life a living hell for years and was one of the only people who actually took Batman completely out of action for an extended period of time when he broke his back.
Bane has been a murderer since he was a child. He not only took out Batman, but he almost killed Nightwing and left him with amnesia.
Hugo Strange
Professor Hugo Strange was a brilliant scientist and psychologist, and he used his access to villains to develop his evil plans. He worked at Arkham for a time and used his job as a psychiatrist to discover Batman's secret identity, which he kept a secret but used to torment the Dark Knight.
Strange has been around since the Golden Age. Still, his recent iterations made him eviler than ever, as he manipulates heroes and villains alike and usually hides behind his Monster Men, who does his dirty work.
Ra's al Ghul
Ra's al Ghul is one of Batman's most persistent villains. While many of Batman's enemies are mobsters who want to control Gotham City, Ra's al Ghul's ambitions are bigger. His name translates to Head of the Demon, and he is an international terrorist and the leader of the League of Assassins.
He is almost pretty much immortal, as he uses his Lazarus Pit to rejuvenate and remain in the fight no matter what happens to him. He has two daughters, including Talia al Ghul, the mother of Damian Wayne.
Victor Zsasz
Victor Zsasz is not one of Batman's A-list villains, but he is as evil as they come. Fans got to know him in the Birds of Prey movie, but he is so much worse in the comics.
Zsasz is a serial killer who keeps track of how many people he kills by making a mark on his body for each murder. His body is covered with these marks, a horrifying reminder that he might be the worst serial killer in Gotham City history.
Joker
Until a few years ago, there wasn't a Batman villain who was eviler than Joker. The Clown Prince of Crime remains someone who doesn't care how many people he kills or how many people he hurts as long as it serves his plan.
His crimes are countless. He murdered Jason Todd by brutally beating him and then blowing the teenager up. He shot and paralyzed Barbara Gordon just to try to drive her father crazy. He threw a newborn baby to the ground so that he could kill Commissioner Gordon's wife as she saved it. Joker is as bad as they come.
The Batman Who Laughs
Joker was only eclipsed on the ranking of Batman's evilest villains by The Batman Who Laughs, which happens to be a mix of Joker and Batman from an alternate world.
He has the intelligence of Batman and the psychology of Joker. He has killed even more people than Joker and has proven to be Batman's greatest enemy. He murdered the Court of Owls, created a Dark Damian, has his own Rabid Robins, murdered his Earth's Justice League, and killed the entire Bat-Family in his world as well.