Don't recall seeing Bruce Greenwood in 'Super 8'?

You didn't, and yet the actor -- who played Captain Pike in J.J. Abrams' 'Star Trek' reboot -- did make a big contribution to the film.

In the 'Super 8' credits, he's billed as "Cooper," yet there's no one named Cooper in the movie. Now the actor is talking about the part he played in the sci-fi movie, one that was more than a little uncomfortable to perform.

Spoilers ahead.

"Cooper" is none other than the film's central character, the angry alien who just wants to go home. He's more than a monster, however, and has one big scene where he's called on to emote. And that's why Abrams tapped Greenwood for the performance.

Greenwood had never done any "performance capture" work before, but when he got a call from Abrams, he figured it was worth a try.

"It's not your typical acting exercise at all, because you're really the only person in this room with all these cameras in it," says Greenwood, told the Montreal Gazette.

"It was a very weird thing to offer up all this big emotion while ... the rest of the people in the room are picking away at the craft services table," he continued. "And you never really how it will turn out because it's all left in the hands of the artists and animators who are putting your work together.

The actor, who built a career in indies like 'The Sweet Hereafter,' admitted the motion capture suit wasn't very flattering. "I saw a bunch of other [big-name] actors who were doing the same thing in other studios ... and there we were: in one-piece Danskins with our pot bellies and saggy asses hanging out," he says.

"All the parts that we try so hard to hide beneath our nice clothes were all of a sudden very visible," says Greenwood, laughing. "Being an actor, you have to be OK with shameless ... and that was it. There was nothing left to hide. It was a big, naked moment ... And that's good. You have to go where it's dangerous."

As for Abrams "lucky charm," Greg Grunberg, the actor does appear in the film, but in nearly as indirect a way as Greenwood: He's credited as "sitcom actor," in a scene in which the TV is on in the background at the Kaznik household. "You really, really [have to] search to find me," Grunberg tells the Associated Press.

[via Montreal Gazette]