PrimeWire

He was the disfigured leader of the “Red Hood Gang” in one version and the chemical bath only changed his mental state. He was a lab tech more often than not, to explain his chemical knowledge. In one version he just wants to retire from his crap boss/job. Robs his work as the “Red Hood” and does the Triple Lindy into a vat of chemicals. In another he can’t support his pregnant wife with the chemistry, while doing stand-up he meets and is set up as a patsy by a gang, or some sh!+, to again rob his job as the “Red Mask”. The betrayal, ending in a Chernobyl-esque spa visit, causes a personality split that sees the joke in the absurdly violent, also due in part to his wife and child dying shortly before this. I think a couple of the versions I’ve read he had a wife and kid that was killed or died from corrupt police or tragedy, but the “Joker” never remembers anything fully after his chemical peel. In one version he is a straight up “G” and obsessively taunts “Batman” to lure him out. This ends poorly, because “Batman” carves the perma grin on his face and rats him out to the mob. I think the version where he kills “Jason Todd” in the “Killing Joke” is the most accepted version. Part of his charm is the varied backstories, it gives him the real aire of crazies, like he’s always squirming and can’t be pinned down.