"The first origin account, Detective Comics #168 (February 1951), revealed that the Joker had once been a criminal known as the Red Hood. In the story, he is a scientist (a chemical engineer) looking to steal from the company that employs him and adopts the persona of Red Hood. After committing the theft, which Batman thwarts, he falls into a vat of chemical waste. He emerges with bleached white skin, red lips, green hair and a permanent grin.
"In his initial dozen or so appearances, starting with Batman #1 (1940), the Joker was a straightforward homicidal maniac, with a bizarre appearance modeled after the Joker playing card. He was slated to be killed in his second appearance, but editor Whitney Ellsworth suggested that the character be spared. A hastily drawn panel, demonstrating that the Joker was still alive, was subsequently added to the comic. For the next several appearances, the Joker often escaped capture but suffered an apparent death (falling off a cliff, being caught in a burning building, etc.), from which his body was not recovered."