With principal photography in full swing for filmmaker Todd Phillips' Joker origin movie starring Joaquin Phoenix as the titular DC Comics villain, the upcoming film has filled out its cast with one absence more glaringly visible than any other: A lack of Bruce Wayne. Perhaps the most recognizable antagonistic relationship in modern fiction, Batman not only stands as a diametric opposite to the Clown Prince of Crime, both thematically and morally, but plays a pivotal role in most accepted origins of the villain, being the one who sends the aspiring criminal into a vat of chemicals leading to his rebirth as the Joker.
The lack of Batman has been underscored by the casting of Brett Cullen as Thomas Wayne, Bruce Wayne's father. With the Wayne family patriarch alive and well, Bruce Wayne is presumably a content child enjoying his family's affluence rather than embarking on his usual nocturnal crusade against Gotham City's criminal underworld. While it is an offbeat approach to the source material, a Joker origin story without Batman is not an entirely new concept.
The idea that the man who would eventually become the Joker is actually a career criminal before his fateful chemical bath is present in virtually every take on the character. However, Alan Moore and Brian Bolland's classic origin story, The Killing Joke, implied that the character was relatively innocent before his sanity snapped as the result of a series of unfortunate events.
This concept has largely been ignored ever since with 1989's Batman, which depicted the character as a mid-level mobster named Jack Napier before his confrontation with Michael Keaton's Dark Knight at the Ace Chemicals factory. Building off this, 1993's animated film Batman: Mask of the Phantasm depicted the character as a mafia hitman responsible for the creation of the titular vigilante in a flashback.
Perhaps the most comparable example is the television series Gotham, which features a young version of the character named Jerome Valeska. The son of circus performers, the budding killer has a visible affinity for carny culture, including clowns, while being a vicious mass murderer without any direct influence from Bruce Wayne. Given that Phoenix's Arthur Fleck has been seen on set palling around with clowns before donning a more circus-influenced look himself, the film might be drawing inspiration from the Fox series.