Boris Karloff
From Jenny Everywhere Wiki
One version of Baron Frankenstein resembled “an aging Boris Karloff”. Pythagoras-858 thought that this was somewhat ironic. (PROSE: The Time of the Toymaker)
Behind the scenes
The actor Boris Karloff became famous starring in Universal Pictures' Frankenstein, not as the Baron, but as Frankenstein's Monster — hence the irony noticed by Pythagoras. However, Karloff did play Baron Frankenstein on several later occasions.