The Original Frankenstein 1931

The film was a big hit. In June 1932 the film had earned reported rentals of $1.4 million.
 Amazing, considering,
average pricing for the movie ticket in the 1930's would be around 5 cents.

 Yes, it was that big of a hit!
 In 1943 Universal reported it had earned a profit of $708,871.
 By 1953 all the Frankenstein films earned.....
 an estimated profit of $13 million.

 Although Frankenstein's hunchbacked assistant is often referred to as "Igor" in descriptions of the films, he is not so called in the earliest films. In both Frankenstein and Bride of Frankenstein, Frankenstein has an assistant who is played both times by Dwight Frye who is crippled.

In the original 1931 film the character is named "Fritz" who is hunchbacked and walks with the aid of a small cane.

In Bride of Frankenstein, Frye plays "Karl" a murderer who stands upright but has a lumbering metal brace on both legs that can be heard clicking loudly with every step. Both characters would be killed by Karloff's monster in their respective films.

It was not until Son of Frankenstein (1939) that a character called "Igor" first appears and was played by Bela Lugosi, and also, revived by Lugosi in the Ghost of Frankenstein (1942) after his apparent murder in the earlier film. This character — a deranged blacksmith whose neck was broken and twisted due to a botched hanging ...... befriends the monster and later helps Dr. Wolf Frankenstein, leading to the "hunchbacked assistant" called "Igor" commonly associated with Frankenstein in pop culture.
Frye appears in later films in the series, such as in Frankenstein Meets the Wolf Man (1943).