The Joker (real name unknown) is a homicidal maniac with a clown-like appearance, bent on creating havoc in Gotham City and fighting a never-ending battle against Batman.
However, through his own actions, Batman has proved a surprise villain, KGBeast, is actually who he seems to hate most, as he bent his iconic no-kill rule and left him for dead on multiple occasions.
Batman and Joker
It is true that Batman also has quite a few memorable villains that comprise a well-regarded rogues' gallery, and people are likely burned out on him battling Joker, but the two have been built up as mortal enemies.
The ultimate Batman villain is a deranged psychopath who acts as more of an agent of chaos than an organised criminal. Also known as the Clown Prince of Crime, the Joker is the arch-enemy of the Dark Knight — one capable of such unthinkable evil that can make even Batman shudder.
Riddler is one of the most intelligent enemies Batman has ever faced, but he's not a fighter.
Why Bruce Wayne Was Afraid Of Lex Luthor. Another reason Batman fears Lex Luthor is because he's the only villain who can match Bruce Wayne's resources. Even Batman's best villains often have to struggle and steal to enact their plans, which means Bruce will always have an advantage with the tools at his disposal.
To Be Forgotten. While fans got to hear many memorable quotes from Joker in Batman: Arkham, the series also revealed what his greatest fear is supposed to be. As it turned out, The Joker feared being forgotten more than anything else because it meant nobody was afraid of him anymore, rendering all his crimes void.
Bane has a great deal of respect for Batman; this isn't a secret, the two have fought many times and even become allies at one point. Bane would even take up the mantle of Batman at a later date, when Bruce is once again not around.
While many may point to the injuries inflicted on Batman by Spawn, Bane, or Hush as the closest he's come to death, one other fight takes the cake. When a Predator showed up in Gotham on a hunt, anyone reading the comic knew he would eventually come into conflict with Batman.
Robin, Batman's vigilante partner, was introduced in the Spring of 1940, Alfred Pennyworth, Batman's butler, was introduced in 1943, and Barbara Gordon was introduced in 1967. The "Batman family", or "Bat-Family", is the informal term for Batman's closest allies; generally masked vigilantes operating in Gotham City.
1 Iron Man
Stark's biggest advantage when going up against someone like Batman are the powerful Iron Man armors in his closet. While Batman has his own armored suit and a few heavier-duty models, Iron Man has a suit built for every occasion and any potential enemy he encounters.
1 The Anti-Monitor
The Anti-Monitor is one of the most powerful DC villains in the comics, so it was only fitting for him to be such a powerful threat when he made his way to live-action.
1) The Dark Knight Metal Batman Who Laughs unleashes the ultimate evil. In the DC Comics event Dark Knight Metal, Batman Who Laughs orchestrated a sinister scheme to plunge the multiverse into darkness. As part of his plan, he created a collection of evil versions of the character unleashed to carry out his bidding.
"I'm an American, I [CENSORED] hate Nazis," Joker says in a panel from Injustice: Year Zero #4 teased by writer Tom Taylor. "I'm a homicidal maniac, not a traitorous bigot."
While he was Robin, Jason Todd saw a number of things in the fear gas, from a Pre-Crisis fear of heights to a Post-Crisis fear of failure to live up to the Robin legacy. These days, he mostly sees clowns.
Heath Ledger died due to accidental drug overdose. Reports even suggested that the actor was depressed after playing Joker in The Dark Knight. The character took a toll on his mentally and physically, so much so, that he suffered from insomnia.
There's no doubt that recalling the fate of his parents is Bruce's biggest fear and regret. No matter who kills Batman's parents in different media, it's the catalyst to the person he becomes. Bruce spent all his childhood and early adulthood scared of remember what had happened.
This raises the question as to why Batman was scared of Lex Luthor specifically. The reason Batman's other villains can't compare is that Lex Luthor is the literal foil to Bruce Wayne. Bruce's greatest fear is becoming the very evil he fights against every night, which explains Batman's no-kill rule. The costumed...
Wayne's phobia of bats is the most apparent. It stems from his childhood incident of falling down a well with bats flying up above him. Because the incident happens at such an impressionable age, it causes extreme fear and becomes impossible to get rid of.
Brainiac 5's IQ surpasses Batman's by many magnitudes, and he could easily master any discipline that Batman has in a much shorter time frame.
The Joker's weakness is his ego. He wants to make Batman laugh, but he mostly likes the idea that he is considered Batman's biggest threat. Joker does not commit crimes because he wants to accumulate wealth. He doesn't do anything out of hatred or anger or fear.
General Dru-Zod is one of Superman's more prominent enemies. Once the Military Director of the Kryptonian Space Center, Zod had personally known Jor-El when he was an aspiring scientist.
In Batman's origin story, Joe Chill is the mugger who murders young Bruce Wayne's parents, Dr. Thomas Wayne and Martha Wayne. The murder traumatizes Bruce, inspiring his vow to avenge their deaths by fighting crime in Gotham City as the vigilante Batman.