Above: Dwight Frye as Fritz in "Frankenstein." Below: Peter Lorre in "M."
The Peter Lorre-Igor Connection
My theory of how Peter Lorre became identified with “Igor, the hunchbacked servant of Doctor Frankenstein,” a role he never actually played:
1) If you watch films from the early 1930s featuring the American actor Dwight Frye, you can see a certain resemblance between him and Peter at that time (little fella, big brown eyes, a tendency not to hold back when cast in melodramatic roles.) Dwight played Fritz, Dr. Frankenstein's lab assistant, in the famous 1931 Universal film, a role that morphed into various incarnations in later Frankenstein pictures, notably Ygor in Son of Frankenstein (memorably played by Bela Lugosi.)
2) From childhood Peter had a chronic lung infection (these were the days before antibiotics) which caused him to develop a condition known as barrel chest in which the ribcage permanently expands, both in front and in back of the thorax. This and the fact that Peter tended to be a little chubby and to collect fat on his back gave him a look that could be interpreted as scoliosis (the condition of having a curved spine or what is impolitely called being a hunchback.)
3) I’m guessing that at some point during the 1950s or 1960s, when entertainers trying to get a cheap laugh did a LOT of Peter Lorre impressions, somebody did a comedy sketch about Dr. Frankenstein in his lab and whoever was playing the lab assistant did a Peter Lorre impression, and that became a thing.
(c) Anne Sharp. All rights reserved.