With the recent announcement that Batman will be in Man of Steel 2, there have been rumors that other Dark Knight characters could make an appearance.

Reports suggest that The Joker, Batman's ultimate nemesis, might be featured in Man of Steel 2. A recent article by ComicBook.com speculated that the film might follow The Dark Knight Returns comic book series, which features The Joker as one of the villains.

The Man of Steel 2 producers are looking for a more "experienced" Batman falling in line with the Batman depicted in The Dark Knight Returns comics. The series also finds Batman teaming up with Superman.

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The Joker's accomplice may also make an appearance in the film if Katie Sackhoff has anything to say about it.

The actress, who starred in Battlestar Galactica as Starbuck, expressed interest in playing Batman villain Harley Quinn. The character is The Joker's girlfriend and accomplice from Batman's various animated series and comic books, but has never been adapted to film.

Sackhoff told Esquire magazine, in an interview published Tuesday, that she was very interested in portraying the villain for the big screen.

"I love Harley Quinn. I do," Sackhoff said, regarding a female superhero she'd like to play. " It's not been done before. It's this fantastic mix. I mean, [Harley's] like the female Joker. Who wouldn't want to do that? . . . I'd probably sell my first born at this point to do that."

Thus far, the only villain presumed to be in Man of Steel 2 is Lex Luthor. However, that could change considering the producers are still in the pre-production stage of the film.

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Man of Steel 2 is projected to be released in theaters in 2015.

Watch this video featuring The Joker and Harley Quinn from Batman: The Animated Series: