And Gaga's rumoured appearance as Harley Quinn isn't even the wildest thing about the reports.
The hit film was a box office smash, but proved to be controversial among viewers and critics.
Joker leads the pack ahead of Netflix's The Irishman And Quentin Tarantino's Once Upon A Time In Hollywood.
Joker, Once Upon A Time In Hollywood and Netflix's The Irishman all have a strong showing.
The convicted paedophile's song Rock And Roll Part 2 features in one of the hit film's key scenes.
One key moment in the new Joaquin Phoenix film stood out to viewers for all the wrong reasons.
In trying to be edgy and provocative, this reimagined Joker is at best tedious and at worst problematic and harmful, writes HuffPost UK's Daniel Welsh
This was either a messed-up moment on the set or a Phoenix prank of the highest order.
Actor Joaquin Phoenix recently walked out of an interview when posed with a question about whether the film could inspire similar incidents in the real world.
The actor says his crash diet to play the Joker helped him move his body in ways he didn’t know he could, reportedly losing more than 23 kilos to play the famed comic book villain for this realistic origin story.