* Warner Bros. plans: They own the rights to the character and ultimately decide when and how he appears.
* Creative teams: Directors, writers, and producers need to agree on a story that justifies Joker's return.
* Audience reception: If previous appearances were successful, it's more likely they'll bring him back.
Here's what we know:
* There is no official announcement for a Joker movie sequel or appearance in other DC films.
* Joker (2019) was a standalone film, so a sequel is not guaranteed.
* There's speculation about Joker's potential involvement in "Joker: Folie à Deux," which is a musical sequel starring Joaquin Phoenix and Lady Gaga, but it's still unconfirmed.
Ultimately, we need to wait for official announcements from Warner Bros. or the creators of the films to know when (or if) Joker will return.