Which movie based on a novel by Mary Shelley was an inspiration for the look of the movie The Whisperer in Darkness?
The Whisperer in Darkness (film):  According to the film's website, the filmmakers intended to capture the look of "classic horror films of the 1930s like "Dracula", "Frankenstein" and "King Kong"". Frankenstein (1931 film): Frankenstein is a 1931 American pre-Code horror monster film from Universal Pictures directed by James Whale and adapted from the play by Peggy Webling (which in turn is based on the novel of the same name by Mary Shelley), about a scientist and his assistant who dig up corpses to build a man animated by electricity, but his assistant accidentally gives the creature an abnormal, murderer's brain.
Frankenstein