Shazam! and Wonder Woman 1984 have the DC Extended Universe covered in 2019, but on top of that, DC and Warner Bros are also releasing the standalone Joker movie next year, with Joaquin Phoenix playing this version of the Clown Prince of Crime. With production scheduled to begin soon, casting reports/announcements have been trickling through in recent weeks, and the latest update is that GLOW star Marc Maron is in talks to join Joker. As for who he would play, supposedly it's the booking agent for the talk show hosted by Robert de Niro's character.
Aside from this booking agent playing a part in booking Joaquin Phoenix's character on Robert de Niro's character's show (duh), Variety didn't provide any other details about this role Marc Maron is being eyed for on Joker. However, given that this talk show appearance plays a role in Phoenix's character being driven to madness, it's possible that this agent is around for that big moment. Once Phoenix's character becomes the Clown Prince of Crime, presumably that means the agent would be on his list of targets. If this booking agent is anything like Maron's other roles, no doubt we can expect him to be curmudgeonly and intolerant of nonsense.
A longtime standup comedian, Marc Maron has been hosting his own podcast, WTF with Marc Maron, since 2009, but on the movie and TV front, his credits include Get a Job, Mike and Dave Need Wedding Dates, Louie and Maron. He was most recently seen reprising Sam Sylvia in Season 2 of the Netflix series GLOW. Assuming Maron signs on the dotted line for Joker, he would join a cast that also includes Frances Conroy as Joker's mother, while Zazie Beetz is in talks to play a single mother who catches the eye of the man who will become The Joker.
Although The Joker has been Batman's arch-nemesis for nearly eight decades, from what's been revealed about the Joker movie so far, it doesn't sound like the Caped Crusader will appear. In fact, so far there's nothing about this movie that screams 'typical comic book adaptation.' Budgeted at approximately $55 million, Joker has been described as a "dark character study" in the vein of Taxi Driver and The King of Comedy, which is even more appropriate description now with Robert de Niro's addition. Set in the 1980s, Joker seems to be taking many cues from The Killing Joke, which portrayed the cackling villain as a failed standup comedian who became insane after "one bad day."