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(created 2011-08-27 20:10):
The Red Hood first appeared in Detective Comics #168 "The Man Behind the Red Hood" (February 1951). In the original continuity, the man later known as the Joker was a master criminal going by the alias of the Red Hood. His costume consisted of a large domed red helmet and a red cape. While attempting to rob a chemical plant, his men were dispatched and then he was suddenly cornered on a catwalk by Batman. Left with no alternatives, he dove into a catch basin for the chemicals and swam to freedom, surviving because of a special breathing apparatus built into the helmet. The toxins in the vat permanently discolored him, turning his hair green, his skin white and his lips red. Upon discovering this, he went insane, and adopted the persona of the Joker.
In Batman: The Killing Joke, Alan Moore wrote an alternate origin of the Joker, and thus the Red Hood; the man who would become the Joker is portrayed as a former chemical engineer, now a struggling stand-up comedian with a pregnant wife. He is approached by the Red Hood gang who want him to lead them through the chemical plant he once worked at, so they can rob the card factory next door. He accepts, in order to make enough money to start a better life for his family. The gang gives him the costume of the Red Hood, which has been worn by many men before; this way, the gang is able to falsely identify the Red Hood as their leader on all crimes they perform when things go wrong. The day of the proposed robbery police inform him that his wife died in a freak accident. He attempts to back out of the robbery, but the gang strong-arms him into keeping his commitment. During the robbery, the plant's security men spot the intruders and shoot the other criminals dead. The engineer tries to flee, but Batman appears and corners him on the plant's catwalk. Terrified, he jumps off the catwalk into the chemical basin to escape. As in the previous origin story, he goes insane after discovering what the chemicals have done to his face, and becomes the Joker. The Joker himself is reluctant to admit that this iteration of his story is definitive, stating: "Sometimes I remember it one way, sometimes another... if I'm going to have a past, I prefer it to be multiple choice!"
A retroactive continuity change appears between the Batman #450-451 story line The Return of the Joker and the graphic novel one-shot Batman: The Man Who Laughs. In The Return of the Joker, the Joker resurfaces after apparently being killed at the end of the Batman: A Death in the Family storyline. In this story, the Joker rummages through his belongings, finds the Red Hood costume and wears it for a robbery in order to regain his confidence and become the Joker again. The Man Who Laughs is a retelling of the first appearance of the Joker, a few months after the Red Hood's plunge into the chemicals, tying the story into both Batman: Year One and The Killing Joke. In this story, Batman is in possession of the Red Hood costume, presumably having discovered it on the banks where the Joker washed up after his swim in the chemical basin.
The Red Hood also makes a brief appearance in Neil Gaiman's "Batman: Whatever Happened to the Caped Crusader?" during the funeral wake scene.
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