One of the characters in the movie "Lady in the Water" has a huge arm. Thye used makeup to make the actor look like he had one really muscular arm while the rest of his body was pretty average.

I was wondering, is this really possible? I mean if someone contentrated on just one body part, say a leg, an arm, their chest or whatever, could they actually make the muscle on it grow that huge while the rest of their body stayed the same?

It just got me wondering is all.

let's see a pic

Yes you could do that. And yes, that was one of the most God awful boring movies ever created.