Ask
most people who the assistant to Dr.
Frankenstein is and they'll tell you it's Igor, the
hunchback. In
Young Frankenstein the hunchbacked assistant is named Igor... or, at least, EYE-gor. Anytime Frankenstein is done as a parody, or part of a cartoon, Igor is almost always present. Regardless of all this, Dr. Frankenstein's assistant was not Igor.
You might think I'm simply complaining about yet another difference between the movie and the book, but there is no Igor in the movie either. The definitive film of Frankenstein is the 1931 version directed by James Whale and starring Boris Karloff as "the Monster". In this version there is a hunchback assistant who fetches a brain, tortures the Monster with a torch and ends up getting killed. But, his name is Fritz. The sequal to Frankenstein, Bride of Frankenstein doesn't have a hunchback at all. But, the sequal (not directed by Whale, but starring Karloff) to Bride, Son of Frankenstein, does have a hunchback assistant named Ygor, and he's played by Bela Lugosi. I imagine this is where the popular idea of Igor came from. The Dr. in this movie is the son of the original doctor in the first movie.