How did the Joker come to be the way he is?
In The Killing Joke, a one-shot written by Alan Moore & drawn by Brian Bolland (released in 1988) the Joker is revealed to be a former engineer at a chemical plant who quit his job to pursue his dream of being a stand-up comedian. However, he was literally booed offstage after only one show, and was left desperate to support his pregnant wife. He agreed to help a group of local crooks rob the chemical plant, but tried to back out after his wife was killed in a household accident. The crooks insisted, and made him wear a red mask to wear so that if the police turned up, he would appear to be the ringleader. When, as predicted, both the police and Batman intervened, the engineer jumped into a vat of chemicals to escape, bleaching his skin white, dying his hair green and damaging the nerve endings in his face, resulting in a permanent, hideous grin. The pain and trauma he had gone through in just one day resulted in his going utterly insane, hence the Joker’s belief that it only takes one
