Call of Duty: Black Ops is getting an injection of celebrity with its next bit of downloadable content. The "Call of the Dead" mission -- part of the upcoming Escalation DLC -- is conscripting a few horror and action alums to be all they can be.

Robert Englund (Nightmare on Elm Street), Sarah Michelle Gellar (Buffy the Vampire Slayer), Michael Rooker (The Walking Dead), and Danny Trejo (Machete) will play roles in the zombie mode. In a bit of meta casting, zombie movie godfather George A. Romero will play himself in the level.

"This is Treyarch's tribute to the legendary George Romero, who truly defined the zombie genre and whose incredible work has been such an inspiration to our team," said game director Dave Anthony in the press release. "It was an absolute honor to work with such an amazing and talented cast whose passion and energy brought their characters instantly to life. Fans are going to love this."

In addition to the Call of the Dead level, Escalation will feature four new competitive multiplayer maps: Zoo, Hotel, Convoy, and Stockpile. It's set for a May 3 release on Xbox Live, with the PlayStation 3 and PC releases following sometime later.