One of the most ironic aspects in Joker: Folie a Deux is the fact that there is constant mention of an in-movie Joker film based on Arthur Fleck’s life. But although we never see this fake movie, director and co-writer Todd Phillips says they almost did film some of it, and it was supposed to star Beetlejuice 2 actor Justin Theroux.

Folie à Deux” is whether or not a television movie that was made based on Arthur Fleck’s life and killing spree (the events of the 2019 film) is actually good or not. Lady Gaga’s Harleen “Lee” Quinzel is obsessed with the TV movie,

Instead, Theroux can be seen in the more lucrative (and better reviewed) other Warner Bros. sequel, "Beetlejuice Beetlejuice."