Despite not being an official part of Warner Bros. slate of DC Comics movies, the still unannounced -- although long in development -- "Justice League Dark" has been at the center of a number of rumors this week. Yesterday's rumors pegged Colin Farrell and Ewan McGregor as likely candidates for John Constantine or Jason Blood, and today's hunch from Heroic Hollywood about the villain the JL Dark will be called together to fight.

According to the site's unnamed sources, Ben Mendelsohn is being eyed for the role of Anton Arcane, Swamp Thing's mad scientist arch-nemesis. The rumor has a twist, though, as it posits that Mendelsohn's involvement in the unnanounced film could depend on the director that producer Scott Rudin hires for the project.

HH's other scoops include news that the WB is considering Monica Belluci ("Spectre") for Madame Xanadu and a balck or Latina actress for the role of Zatanna.

Mendelsohn is currently attached to the first Star Wars anthology film, "Rogue One," which hits theaters on December 16, 2016. While "Justice League Dark" does not yet have a release date, the film is rumored to begin production in 2016.