He's not muscular at all! Look at the massive double chins and double everything on the guy:That's very subjective, based upon who's drawing him. I've seen him drawn as a straight up musclehead...a tall guy with like 2% body fat and mounds of muscle; but, I have also seen him drawn in a way that might be very alluring to some of the female population of this board.
I don't really do anime, but a quick google search says his name is Dr. Kosaku Tokita
Compare him to the size of his partner as they explore the abandoned amusement park:
Here's short "making of" video about the amusement park scenes:
Random stills from Paprika:
He practically takes up the whole elevator! He and Paprika are having a tiff in this scence: