"The Devil Wears Prada" actress Emily Blunt is reportedly joining the cast of "Iron Man 2" as the villainess Black Widow.

Director Jon Favreau and Marvel Entertainment are said to be looking for the right actress to play Natasha Romanoff, Black Widow's human name, and the 25-year-old actress is the frontrunner for the part, Variety reports.

It has recently been reported that "The Wrestler" star Mickey Rourke and Sam Rockwell are negotiating to play villains in the film. Rourke would play Crimson Dynamo, while Rockwell would be Justin "MC" Hammer.

Robert Downey Jr. will be reprising his role as the titular superhero along with Gwyneth Paltrow as his assistant Pepper Potts. "Iron Man 2" is scheduled to hit theaters on 2010.