It was Bela Lugosi. Boris Karloff had retired from the role at that point.

This message has been deleted.

after watching Wolfman meets Frankenstein on AMC the other day I did notice that Boris or whoever was the monster in the movie he seemed shorter than usual. Dunno how tall Boris was with the big platform clonker shoes in Frankenstein but jeez, Frankenstein's creation was short and the same height as Larry Talbot

In this movie, Bela Lugosi played the Monster for closeups, and Eddie Parker played him for all the active scenes. However neither the 6' Karloff or 6'1" Lugosi would have fared very well against the 6'2' Lon Chaney, even with the 4" boots Karloff supposedly wore. The Monster does look small in several scenes compared to Chaney, who himself was the second tallest actor to play the classic Universal Monster, after 6'5" Glen Strange.