The most common story involves him falling into a tank of chemical waste that bleaches his skin white, turns his hair green and lips red, and leaves him with a rictus grin; the resulting disfigurement drives him insane.

The Joker possesses no superhuman abilities, instead using his expertise in chemical engineering to develop poisonous or lethal concoctions and thematic weaponry, including razor-tipped playing cards, deadly joy buzzers, and acid-spraying lapel flowers.

In a 1975 interview in The Amazing World of DC Comics, Robinson said he wanted a supreme arch-villain who could test Batman, not a typical crime lord or gangster designed to be easily disposed of.

[20] By issue #13, Kane's work on the syndicated Batman newspaper strip left him little time for the comic book; artist Dick Sprang assumed his duties, and editor Jack Schiff collaborated with Finger on stories.

The backlash was inspired by Frederic Wertham, who hypothesized that mass media (especially comic books) was responsible for the rise in juvenile delinquency, violence and homosexuality, particularly in young males.

[2] The Comics Code banned gore, innuendo and excessive violence, stripping Batman of his menace and transforming the Joker into a goofy, thieving trickster without his original homicidal tendencies.

[2][27] After the TV series ended in 1969, the increase in public visibility had not stopped the comic's sales decline; editorial director Carmine Infantino resolved to turn things around, moving stories away from child-friendly adventures.

[28] The Silver Age introduced several of the Joker's defining character traits: lethal joy buzzers, acid-squirting flowers, trick guns, and goofy, elaborate crimes.

[39] While O'Neil and Adams' work was critically acclaimed, writer Steve Englehart and penciller Marshall Rogers's eight-issue run in Detective Comics #471–476 (August 1977–April 1978) defined the Joker for decades to come[31] with stories emphasizing the character's insanity.

[45][31] Several months after Crisis on Infinite Earths launched the era by killing off Silver Age icons such as the Flash and Supergirl and undoing decades of continuity,[46] Frank Miller's The Dark Knight Returns (1986) re-imagined Batman as an older, retired hero[47] and the Joker as a lipstick-wearing celebrity[36][48] who cannot function without his foe.

[52] Alan Moore and Brian Bolland's 1988 graphic novel The Killing Joke expands on the Joker's origins, describing the character as a failed comedian who adopts the identity of the Red Hood to support his pregnant wife.

Breyfogle conceived the idea as a means to expand on Anarky's characterization, but O'Neil (by then the editor for the Batman series of books) was opposed to it, and only allowed it to be written under protest, and with a promise that the revelation would eventually be revealed incorrect.

[19][62] Capullo's Joker design replaced his traditional outfit with a utilitarian, messy, and disheveled appearance to convey that the character was on a mission; his face (surgically removed in 2011's Detective Comics (vol.

[42] Detective Comics #168 (1951) introduced the Joker's first origin story as the former Red Hood: a masked criminal who, during his final heist, vanished after leaping into a vat of chemicals to escape Batman.

Batman arrives to stop the robbery, provoking the terrified comedian into jumping into a vat of chemicals, which dyes his skin chalk-white, his hair green, and his lips bright red.

[50] The Joker temporarily escapes justice when Ayatollah Ruhollah Khomeini appoints him the Iranian ambassador to the United Nations, giving him diplomatic immunity; however, when he tries to poison the U.N. membership, he is defeated by Batman and Superman.

[95] "Case Study", a Paul Dini-Alex Ross story, describes the Joker as a sadistic gangster who creates the Red Hood identity because he misses the thrill of committing robberies.

[98] In The Brave and the Bold #31, the superhero Atom enters the Joker's mind and sees the criminal's former self - a violent sociopath who tortures animals, murders his own parents, and kills for fun while committing robberies.

[87][100] A number of alternate universes in DC Comics publications have allowed writers to introduce variations on the Joker, in which the character's origins, behavior, and morality differ from the mainstream setting.

[125] The Killing Joke (in which the Joker is the unreliable narrator) explains the roots of his insanity as "one bad day": losing his wife and unborn child and being disfigured by chemicals, paralleling Batman's origin in the loss of his parents.

[117] Comics scholar Peter Coogan describes the Joker as trying to reshape reality to fit himself by imposing his face on his victims (and fish) in an attempt to make the world comprehensible by creating a twisted parody of himself.

"[132] The villain has been temporarily rendered sane by several means, including telepathic manipulation by the Martian Manhunter[71] and being resurrected in a Lazarus Pit (an experience typically inducing temporary insanity in the subject).

[137] He commits crimes with a variety of weaponized thematic props such as a deck of razor-tipped playing cards, rolling marbles, jack-in-the-boxes with unpleasant surprises and exploding cigars capable of leveling a building.

[30][138] However, his chemical genius provides his most-notable weapon: "Joker venom", a liquid or gaseous toxin that sends its targets into fits of uncontrollable laughter; higher doses can lead to paralysis, coma or death, leaving its victim with a ghoulish, pained rictus grin.

His technical genius is not limited by practicality, allowing him to hijack Gotham's television airwaves to issue threats, transform buildings into death traps, launch a gas attack on the city and rain poisoned glass shards on its citizens from an airship.

He has collaborated with criminals like the Penguin, the Riddler, and Two-Face, although these partnerships rarely end well due to the Joker's desire for unbridled chaos, and he uses his stature to lead others (such as Killer Croc and the Scarecrow).

[151] Despite his tendency to kill subordinates on a whim, the Joker has no difficulty attracting henchmen with a seemingly infinite cash supply and intimidation; they are too afraid of their employer to refuse his demands that they wear red clown noses or laugh at his macabre jokes.

[153][154] Introduced in the 1992 animated series, Quinn is the Joker's former Arkham psychiatrist who develops an obsessive infatuation with him and dons a red-and-black harlequin costume to join him as his sidekick and on-off girlfriend.

[188] The character has been the focus of ethical discussion on the desirability of Batman (who adheres to an unbreakable code forbidding killing) saving lives by murdering the Joker (a relentless dealer of death).

[206] The Joker is one of the few comic book supervillains to be represented on children's merchandise and toys, appearing on items including action figures, trading cards, board games, money boxes, pajamas, socks, and shoes.