The Joker origin movie might borrow a plot point from The Killing Joke
Warner Bros. origin movie about the Joker, which has Martin Scorsese on board as a producer and Joaquin Phoenix supposedly in talks to star as the Clown Prince Of Crime himself, has always seemed like the kind of idea that’s too bizarre to ever actually happen. For one thing, Warner Bros. already has a guy set to play the Joker in multiple movies, and he’s not too happy about having to share the purple suit with another actor known for doing weird shit, and for a second thing, DC Comics has always sidestepped any attempts to give the Joker a true, definitive origin. Even The Dark Knight acknowledged that the Joker is scarier when you don’t know his origin, with Heath Ledger offering multiple conflicting backstories throughout the movie.
If this movie does happen, though, director Todd Phillips might be pulling some inspiration from one of the few times the comics did try to explain where the Joker came from. According to The Wrap, Phillips’ movie will feature a pre-insane Joker as a “failed 1980s comedian” who becomes a criminal “after bombing with audiences.” This is supposedly going to be a “gritty crime movie,” so it probably won’t be as simplistic as that, but the idea of the Joker being a struggling stand-up before he started tormenting Batman comes from Alan Moore and Brian Bolland’s The Killing Joke.
In the comic (which is somewhat non-canonical, depending on how you read the ending), the Joker is a struggling comedian named Jack who agrees to work with some criminals so he can support his pregnant wife. He then finds out that his wife was killed in an accident while he was helping the criminals plan a heist that involved breaking into a chemical plant, but they make him go through with their scheme anyway. He gets set up as a patsy to distract Batman while the other guys get away, eventually leading to him falling into some chemicals that make his skin white and his hair green. This horrible series of events causes him to snap, turning him into the Joker.
We may have just spoiled the whole Joker movie, but as we said up above, it seemed like a weird idea anyway. (Also, they did just make The Killing Joke into an animated movie.)