Mila Kunis will be Natalie Portman's nemesis. The actress, who played Jason Segel's love interest in "Forgetting Sarah Marshall," is in discussions to star opposite Portman in Darren Aronofsky's supernatural drama "Black Swan." The movie centers on a talented ballerina (Portman) in the New York City Ballet who is tormented by a rival who might or might not be a figment of the dancer's imagination. Kunis will play the rival, Lilly.

Kunis was among the standouts at Comic-Con during the pop-culture convention this past weekend. She appeared to promote her roles in the Denzel Washington-starring "The Book of Eli," the Ben Affleck-toplined comedy "Extract" and her voice role in the animated Fox series "Family Guy."She also is set to co-star in the relationship comedy "Date Night" alongside Steve Carell and Tina Fey.

"Black Swan," which is set to begin shooting in the fall in New York, does not yet have a distribution deal. Aronofsky's last film, "The Wrestler," was distributed by Fox Searchlight.