Treyarch's Jimmy Zielinski has said the Call of the Dead portion of the Escalation pack for Black Ops was created due to the popularity of the unlockable Presidents map from the game's single-player campaign.
Speaking with Joystiq at a recent press event regarding Call of the Dead's creation, Zielinski said part of the creation of the mode was in response to the community and user testing.
"We just realized how popular [the President's map] was, we kind of thought already, 'When are we going to do this again and what is it going to be?'"
So the team started mulling around who would be a fun character to play as, and when it came time to court actors to lend their likenesses to Call of the Dead, it didn't hurt matters that most all had already heard of the Call of Duty series.
Matter of fact, the hollywood folks present in Call of the Dead, George Romero, Michael Rooker, Sarah Michelle Gellar, Robert Englund, and Danny Trejo, "had already either heard of the game or had a first-hand experience with it."
"Call of the Dead is, simply put, Treyarch's homage to the granddaddy of zombies," said Zielinski regarding the addition of George Romero to the game. "His movies have served as such an inspiration to us. We're all really happy with our choices and their performances, and it sounds like the fans are responding as well."
Zielinski could provide Joystiq with any numbers on just how popular the zombie modes in the Call of Duty series are with the fans, but according to him, they are "feverish," about the game and "jazzed up," they were regarding Call of the Dead.
"I don't know that we have actual data to divide the pile or anything like that but it is seen as very important," he added, "and it's given backing as such."
The Escalation pack is out now on Xbox Live with a PC and PS3 release date to be determined.