Doctor Septimus Pretorius is a fictional character who appears in the Universal film Bride of Frankenstein (1935) as the main antagonist.

[3] Doctor Pretorius is a renegade mad scientist who persuades Henry Frankenstein to resume his experiments with bringing dead flesh to life.

He eats a picnic dinner in a crypt, trades prissy banter with the Monster, and laments that the tiny ballerina he created "will only dance to Mendelssohn's 'Spring Song'".

A professor of philosophy at the University of Ingolstadt, Pretorius first points young Henry on the path toward his unwholesome experiments in giving life to the dead.

Bride of Frankenstein director James Whale was openly gay and frequently included camp elements in his films.

He directed Thesiger (himself identified in some sources as more or less openly gay)[4] to play the part as an "over the top caricature of a bitchy and aging homosexual".

Pretorius serves as a figure of seduction and temptation, pulling Frankenstein away from his bride on their wedding night to engage in the "unnatural" act of non-procreative life.

In the Amicus horror film The House That Dripped Blood (1970), Geoffrey Bayldon, playing a mysterious antique shop owner, is made up and costumed to look like Ernest Thesiger as Pretorius.

[citation needed] In the 1973 NBC-TV miniseries Frankenstein: The True Story, James Mason portrays a Pretorius-like figure named Dr. Polidori (named for Lord Byron's real-life physician, John William Polidori, who was part of the 1816 gathering that produced Mary Shelley's novel and also the author of the story "The Vampyre").

The 1986 film From Beyond adds a Dr. Edward Pretorius at Miskatonic University (played by Ted Sorel) as a dark mentor for Crawford Tillinghast (Jeffrey Combs).

This Pretorius is an impotent sadist (with a room full of bondage gear) who is assimilated by "the Beyond" and attempts to drag others into it, boasting that the pineal gland growth brought on by the resonator is like "an orgasm of the mind".

In Mary Shelley's Frankenhole (2010-2012), the character Professor Sanguinaire Polidori (voiced by Scott Adsit) is based on Septimus Pretorius.