The Joker is the arch-nemesis of Batman, representing the chaos to Batman's order. Initially, the Joker appeared to be little more than a colorful crook with a penchant for gimmicks, but as the years passed, his crimes became ever more gruesome, a possible reflection of his own increasingly downward spiral into insanity.
The Joker was once the criminal Red Hood, who planned to steal $1,000,000 and then retire back into obscurity. However, after an accident at the Ace Chemical Processing Plant involving chemicals, his skin turned white, his hair green and his lips red, contorting his facial muscles into a perpetual malignant grin. The incident also drove the man irrevocably insane and he dubbed himself the Joker, becoming the most dangerous criminal of Gotham City and one of Batman's most notorious adversaries.
Although the Joker preferred working alone (a ubiquitous horde of henchmen not withstanding), he occasionally teamed up with criminal mastermind Lex Luthor, and together they matched wits against the "World's Finest" team of Batman, Robin and Superman.
Gotham City was the Joker's favorite location for his criminal activities. For this reason, he was confronted by Batman on several instances. When Joker impersonated a filmmaker and performed crimes posing as iconic comedians, his ultimate goal was to steal from a wealthy film fanatic, but his plans were foiled by Batman and Robin. The Joker tried several more harmless criminal schemes, but the outcome was always the same. The Joker's early career crescendoed with his ruination of the stable status quo which had existed for the Justice League up until that point. Creating a false identity as "John Dough," the Joker started a populist mass-movement calling for exaltation of the average as the pinnacle of American life and vilification of the extraordinary and bizarre. Specifically, John Dough's animus was focused at superheroes for their larger-than-life, colorful personae, which he had convinced his followers made a mockery of the common working man. Of course, the great irony was that this "champion of the average" was truly more freakish and unusual than the very heroes he was denouncing. Nevertheless, using the identity of John Dough, the Joker manipulated the JLA's teen mascot Snapper Carr into doing his bidding, revealing the location of the League's Secret Sanctuary to him, and helping set up Batman for an ambush. Joker then imprisoned Batman in a room with a limited air supply with nothing but a TV monitor to show him the destruction of the rest of the League. The Joker used a mind-altering ray to inflame the masses into a riot as he summoned the JLA members before him and rebuked them for insulting the average American with their ways, while Batman used the pressurized oxygen canister in his room and a loose wire from the TV monitor to set off an explosion from rapid thermal expansion. "John Dough" blamed the mob violence on the JLA and went to Washington, D.C., to lobby the United States Congress to ban the Justice League. Just at that moment, Batman burst in the room and threatened to expose John Dough's identity, causing Dough to firebomb the Capitol Building in order to make his getaway. The Justice Leaguers then pursued Dough back to their Secret Sanctuary, where he tried to use weapons from the JLA trophy room against them, but Black Canary took Dough out with her newly obtained power of sonic-wave emissions, after which Batman unmasked John Dough as having been the Joker the whole time. This incident was directly responsible for causing the JLA to evacuate the Secret Sanctuary for their new satellite HQ in Earth's orbit, in addition to terminating Snapper Carr's long association with the Justice League as their civilian confederate.
After his last caper, the Joker was captured and sent to a mental hospital for the criminally insane. The Joker's mental condition worsened and when he learned that one of his thugs had double-crossed him, the Joker broke out of the hospital and went on a murdering rampage, killing his former henchmen using his trademark Joker Venom, among other methods. With this new criminal mindset, the Joker was able to knock Batman unconscious and had the chance to kill him once and for all, but he refused to do so and in the end, it allowed Batman to capture the Joker and bring him back to the authorities.
Somehow, the Joker escaped and murdered a whole family, making the crime look like a frame-up from other criminal. Batman fell for the Joker's gag and he tried to help the Joker capture the real culprit. The Joker used Batman and led him to a trap, but Batman managed to survive and captured the Joker as he tried to escape using the Batmobile. Not long after this, the Joker escaped from Arkham, even though Batman tried to stop him. Joker managed to dose Batman with a special variation of Joker venom, which could kill the Dark Knight from laughter in 72 hours. The Joker murdered one of the scientists capable of creating a cure, but Batman reached the second doctor and captured the Joker by overcoming the urge to laugh. In the end Batman was cured and the Joker locked up. However, the Joker escaped and he poisoned an entire prison as a result of his plan to poison a former henchmen. The Joker then got hold of the antidote and forced Batman to fight against Wildcat. The heroes managed to retrieve the antidote and captured the Joker.
Fiend or Foe
The Joker started having conflicts with the rest of Batman's enemies and he always proved to be superior or equal to them. When Two-Face escaped from Arkham leaving the Joker behind, the criminal clown broke out and thwarted Two-Face's criminal plot, resulting in both of them being taken back to Arkham. After this, the Joker was sprung out again by Willy the Weeper, who wanted the Joker's assistance on a crime. The Joker tried to double-cross Willy and they both were captured by the authorities. Later, the Joker started a series of robberies and The Creeper was blamed for them. This led to a confrontation between them in which Creeper lost his memory. The Joker tried to capitalize on this amnesia, but when Creeper recovered, the Joker was defeated and captured once again.
Later on, the Joker tried to start a crime spree in Star City, where he also tried to get Dinah Lance to marry him. He was promptly stopped by Green Arrow, but this time the Joker was not captured by the authorities. Eventually, the Joker reappeared in Wisconsin, where he started another caper and caused the capture of the Royal Flush Gang after they became enemies on their quest to steal valuable art pieces. Later, the Joker replicated crimes from the Sherlock Holmes stories, but his plans were eventually thwarted by a real life Sherlock Holmes.
After this, the Joker caused an accident during one of Lex Luthor's experiments, which caused them to switch personalities, but the change was soon reverted. It was around this time that the Joker created a secret passageway between his cell in Arkham Asylum and his secret Ha-Hacienda hideout. Using this means of escape, the Joker stole a fear gas developed by S.T.A.R. Labs, which caused the master criminal of fear, the Scarecrow to confront him. The Joker outsmarted the Scarecrow and then he returned to his cell in Arkham to throw off the police's suspicions. The Joker then tampered with a famous actor's film to include himself, but during the crime he was confronted by Catwoman, who wanted to steal the actor's valuable cat. The Joker was defeated and locked back in Arkham, but he got the last laugh.
Learning from past mistakes, the Joker and Two-Face teamed up to steal a valuable item from Oliver Queen and this attracted attention from Green Arrow, Batman and the Atom. Although the heroes managed to retrieve the item, the Joker and Two-Face weren't captured.
Later, the Joker escaped from Arkham again and the final confrontation between him and Batman took place in a house of mirrors, where the Joker was recaptured. Eventually during one of his regular crimes, the Joker came across a man disguised as Batman and he killed the innocent, believing he was the real Batman. When word about Batman's death spread, the Joker was summoned to a trial among criminals and told the story of his victory over Batman. However, the whole trial turned out to be one of Batman's plans in order to find the killer of the innocent man and after the Joker confessed his crime, he was captured by the Dark Knight and returned to Arkham.
The Laughing Fish
The Joker eventually escaped and attended an auction organized by Hugo Strange to reveal Batman's identity. The Joker wanted to prevent that from happening, but when he learned that Strange had mysteriously disappeared, he assumed some of the other criminals must have eliminated him; namely Rupert Thorne. Once that was taken care of, the Joker set his next plan in motion and he used a chemical across the shores of Gotham that contaminated the waters, transforming the fish to grotesque creatures with the Joker's face on them. The Joker's goal was to secure trademark for the "Joker Fish", but when he was denied, because of the law, the Joker started a killing spree against public servants, announcing their deaths and killing them with his trademark Joker Venom.
The Joker managed to claim two victims thanks to his careful planning, but during his third murder attempt, he was stopped by Batman. the Joker tried to escape, but Batman chased him through the rooftops of Gotham until they reached a construction site, where the Joker was shocked by lightning and fell to the river below. The Joker didn't come up after that last blow, but this was not his demise.
Return of Madness
True to form, the Joker returned soon and started a loan shark business, killing his clients when they refused to pay his fees. This new crime caught the eye of Batman, who teamed up with Black Canary, the Joker's past crush, and managed to put an end to the Joker's crime spree with some vital help from Bruce Wayne's butler, Alfred. The Joker's next scheme consisted of kidnapping several of Batman's allies including Robin, Commissioner Gordon and Alfred. He placed them in a death trap to lure Batman, but his plan was ultimately thwarted by the Dark Knight. In the ensuing confrontation, the Joker met his apparent demise as his escape vehicle blew up in flames. As usual, the Joker survived and he was locked in Arkham under undisclosed circumstances. He eventually escaped and returned to Gotham with a new scheme to murder Batman using deadly toys. The Joker's crimes and clues were left deliberately, as he wanted to lure Batman into his trap. His plan succeeded and Batman was forced to fight several deadly toys until death. However, Batman found a way to stop the toys and the Joker was subsequently captured.
When the Penguin was apparently murdered by the Joker, the Clown Prince of Crime sought help from Batman to clear his name and together they uncovered a plot to frame him by the same Penguin. Later, the Joker tried to murder Batman at the same time as he carved a giant bust with his face. His plan was once again thwarted by Batman. When the Joker learned about a new and uprising crimelord in Gotham called Killer Croc, he gathered many of Batman's greatest foes and prepared a plan to eliminate both Batman and Croc at the same time. Of course, this plan failed and the Joker was unintentionally defeated by Croc.
Having escaped from Arkham again, Joker relocated to Guatemala, where he planned to take over the country by creating an armed conflict between the people. When he learned that reporter and photographer Vicki Vale was investigating his activities, he kidnapped her, which in turn drew the attention of Batman. Although Batman managed to foil the Joker's plans, the Joker was only brought down by the combined work of Batman and the new Robin, who arrived in time to assist Batman against the Joker, securing victory.
On his last criminal act, the Joker was among the various inmates released from Arkham Asylum by Ra's al Ghul to eliminate Batman, but despite their combined efforts, they were ultimately defeated by the Dark Knight and his allies. After the events of the Crisis on Infinite Earths, Joker's existence and history was completely altered, transforming him into a different person, existing on a different reality.
- Mental Illness: Joker has been locked away in Arkham Asylum for the Criminally Insane on several occasions.
- Joker Venom, and any number of weapons disguised as props, such as exploding fish or lapel flowers that spray acid. Famously, in Batman #321, he uses a gag gun that at first only shoots out a small flag that says "BANG! YOU'RE DEAD!", lulling his victim into a false sense of security, but on the trigger's second pull fires the sharp-tipped flag out like a spear and kills the man.
- Joker Fish: The Joker used his Joker Venom to turn all of the fish in Gotham Bay into maniacally, grinning Joker-Fish. Consuming a Joker Fish had the same effect as one who had been subjected to the Joker Venom directly. In one instance, a house cat ate a Joker Fish, was Jokerized, then attacked its master, transmitting the venom, ultimately killing him.
- The Earth-One Joker shares many similarities with his Earth-Two and New Earth counterparts. Their origins, career history, personalities and physical appearance are nearly identical to one another. The establishment of the Earth-One Joker is the result of retroactive alteration to the character's established published history (colloquially known as a Retcon). The Joker's actual first appearance as an Earth-One character is a matter of interpretation as there has never been an actual distinction between when the Golden Age Earth-Two Joker ceased making regular published appearances and when the Silver Age Joker was introduced. It is commonly accepted that most appearances made by the Joker from the early-mid 1950s until 1986 are attributed to the Earth-One Joker. The Red Hood origin was revisited for the Modern era Joker in Alan Moore's 1988 one-shot special Batman: The Killing Joke. It is also unknown how much of the Joker's Pre-Crisis history survived into his Post-Crisis chronology. While many of his earlier appearances from the 1950s and 60s are likely apocryphal, it is reasonable to assume that many of the Joker stories presented in the 1970s-80s were still part of Post-Crisis continuity.
- The Joker is the first DC Comics super-villain to receive his own ongoing comic book series.
- The Joker's favorite TV show is The Three Stooges.
- 135 Appearances of Joker (Earth-One)
- 41 Images featuring Joker (Earth-One)
- 20 Quotations by or about Joker (Earth-One)
- Character Gallery: Joker (Earth-One)
- The Joker #4
- Batman #353
- Detective Comics #476
- Justice League of America #77
- The Joker #10
- Untold Legend of the Batman #2
- World's Finest #88
- World's Finest #177
- Detective Comics #341
- Detective Comics #322
- Detective Comics #365
- Detective Comics #388
- Justice League of America #78
- Justice League of America #100
- Justice League of America #114
- Justice League of America #130
- Batman #251
- The Brave and the Bold #111
- Batman #260
- The Brave and the Bold #118
- The Joker #1
- The Joker #2
- The Joker #3
- The Joker #5
- The Joker #6
- The Joker #7
- The Joker #8
- The Joker #9
- The Brave and the Bold #129
- The Brave and the Bold #130
- Batman #286
- Batman #294
- Detective Comics #472
- Detective Comics #475
- The Brave and the Bold #141
- Batman #321
- Detective Comics #504
- The Brave and the Bold #191
- Detective Comics #526
- Batman #365
- Detective Comics #532
- Batman #366
- Batman #400