The Joker Begins as the Red HoodIn Detective Comics #168's "The Man Behind the Red Hood" (1951), Batman enlists the help of criminology students to discover the identity of the Red Hood. Never seen without the smooth hood masking his features, the criminal had disappeared ten years earlier.
Batman learns that the Red Hood, a lab worker, had decided to steal $1 million and retire. But after robbing the Monarch Playing Card Company, he escaped Batman by swimming through a vat of chemicals. His hair turned green; his skin, white; and his lips, red. He became the Joker, motivated to a new life of crime based on the playing card he resembled.
The Failed Comedian of The Killing Joke
This origin inspired Alan Moore and Brian Bollard's The Killing Joke (1988), in which the Joker begins as a failed comedian who becomes the Red Hood for one night only to support his family. Even after his pregnant wife dies in an accident, mobsters force him to go through with the job – robbing the payroll of a chemical plant.
The robbery goes wrong, and the Red Hood falls into the chemicals as before. But in the new version the Joker's psychological motivations are explored much more fully. His disfigurement, added to his domestic tragedy, drives him insane.
In Legends of the Dark Knight #50 (1993), Dennis O'Neil penned an origin based on the Joker's debut in Batman #1. The milestone issue gives a glimpse into his family life before his criminal career.
In this version, the Joker dominates his idiot-savant cousin, Melvin. The child-like Melvin has a brilliant scientific mind, which the Joker exploits to invent the Joker venom for use in a blackmail scheme. Later, as Batman closes in, the Joker murders Melvin in an attempt to cover his tracks. But Batman isn't fooled – he recognizes the Joker as the former Red Hood, and captures him.
Not Even His Girlfriend Knows
Bruce Timm and Paul Dini's one-shot Mad Love (1994) explores the bizarre romance between the Joker and Harley Quinn. Though it is more the origin story of Harley, first introduced in Batman: The Animated Series, some clues – or non-clues – about the Joker's beginnings are dropped.
Flashbacks reveal that before she became Harley, Dr. Harleen Quinzel had treated the Joker in Arkham Asylum. She had fallen in love with the psychotic clown when the Joker told her how "My father used to beat me up pretty bad." But, later in the story, Batman reveals that the Joker's story is a lie. "He's got a million of them, Harley," he says. "Like any other comedian, he uses whatever material will work."
Joker Origins for the Twenty-First Century
In Batman Confidential #7-12 (2007-2008), the man who will become the Joker is already a criminal genius – but he's bored with crime, until Batman "inspires" him. A failed mob hit, in this most recent version, leads to his disfiguring chemical bath.
Interestingly, one of Batman's "batarangs" slices the Joker's mouth in the story, giving him his scarred and exaggerated grin. A similarly scarred Joker appears in Brian Azzarello and Lee Bermejo's graphic novel Joker (2008), and underlies Heath Ledger's portrayal in The Dark Knight (2008).
Different writers and artists have retold the Joker's backstory over the years, sometimes contradicting, sometimes assimilating earlier versions. But when even the Joker himself has "a million of them," there will likely never be a "true" origin of the Joker.