Re: The Official Batman (1989) Thread - Part 3
Last night I re-read the first Black Mask story. Sam Hamm definitely ripped this off and imposed lots of stuff on the Joker.
It's clear now: Nicholson's Joker = Black Mask + Cesar Romero (Silver Age Joker)
So the Joker wasn't based on "Five Way Revenge", "The Dark Knight Returns", "The Killing Joke", "The Laughing Fish" and whatever (not that those stories are all good).