Lady Gaga and Joaquin Phoenix appear in "Joker: Folie à Deux"

Lady Gaga and Joaquin Phoenix appear in "Joker: Folie à Deux"

Lady Gaga looks to be off the deep end with her new character.

Lady Gaga looks to be off the deep end with her new character.

Phoenix won a best actor Academy Award for the original 2019 DC film

Phoenix won a best actor Academy Award for the original 2019 DC film

The singer/actress is believed to be playing Harley Quinn in the “Joker” sequel, “Joker: Folie à deux.”

The singer/actress is believed to be playing Harley Quinn in the “Joker” sequel, “Joker: Folie à deux.”

The caption on the photo read simply, “Folie à Deux” with a joker emoji.

The caption on the photo read simply, “Folie à Deux” with a joker emoji.