Septimus Pretorius is a fictional character who appears in the Universal film Bride of Frankenstein (1935). He is played by British stage and film actor Ernest Thesiger. Some sources claim he was originally to have been played by Bela Lugosi or Claude Rains. Others indicate that the part was conceived specifically for Thesiger.
Doctor Pretorius is a renegade mad scientist who persuades Dr. Henry Frankenstein to resume his experiments with bringing dead flesh to life. An amoral egomaniac, he has no regard for human life or ethics and cares only for his own prestige as a scientist.
Along with his sinister qualities, Pretorius is responsible for a large share of the film's dark humor. 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.'" He claims that gin is his only weakness. Then later in the film, he claims his cigars are his only weakness when he first meets the Monster. Pretorius also delivers the famous toast "To a new world of gods and monsters!" midway through the film.
Pretorius is based on the Monster's own personality from the original novel.
Frankenstein's former teacher Septimus Pretorius is a tall, emaciated-looking man with an unusually large nose and devilish pointed ears. 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. He himself is "booted out" from his teaching post "for knowing too much." Pretorius seeks out his former student after learning that the Monster has survived being trapped in the burning windmill in the climax of the first film. Pretorius himself acknowledges that he may be insane in a conversation with Frankenstein by quoting "You think I'm mad? Perhaps I am!"
Pretorius performs experiments creating life similar to Henry's. He unveils to Henry a group of various homunculi—miniature living humans which he has kept in bottles and claims to have grown from "seed" like cultures. Each figure represents a different character:
- A Queen which he claims was his first experiment.
- A King which is madly in love with the Queen and has a resemblance to Henry VIII. Pretorius has to be very careful with the King and work to keep the King and Queen separated. This is even shown when the King briefly breaks out of his bottle only to be caught by Pretorius and put back in his bottle with his cup on top of the bottle.
- An Archbishop which disapproves of what the King is doing to win the Queen's heart.
- The Devil who is depicted as a man in a black suit and a cape. Pretorious gleefully compares his own visage to that of the Devil by quoting "There's a certain resemblance to me, don't you think? Or do I flatter myself?" He says sometimes, he thinks life would be more interesting if they were all devils.
- A Ballerina dancer who will only dance to Felix Mendelssohn's "Spring Song".
- A Mermaid grown from "an experiment with seaweed" which lives in a water-filled bottle.
- An Infant who was mostly edited out except for certain camera shots.
He has been unsuccessful in creating a full-sized human. He proposes to Henry that together they create a mate for his monster with Henry building the body and Pretorius supplying an artificially-grown brain. Henry initially balks at the idea, but Pretorius reminds him that he is capable of exposing him to the authorities as the creator of the Monster who has done so much damage.
Later, he meets the Monster in a crypt where he has gone to steal bodies and is dining using the top of a coffin as a picnic table. When the Monster asks him "Friend?" he gives him the remains of his chicken. He tells the Monster of his plans to create a mate for him.
The Monster, eager for companionship of any kind, considers Pretorius his friend. From then on, the Monster is willing to do anything that the impish scientist desires such as kidnapping Henry's wife Elizabeth Lavenza in order to force him to help Pretorius. Henry agrees and together the two scientists create the Bride of Frankenstein. Unfortunately, even the Bride finds her would-be husband repulsive and the heartbroken Monster decides to end his life by blowing up the laboratory. He instructs Henry and Elizabeth to run, but barks at Pretorius and the Bride to stay saying that they "belong dead". Before Pretorius can move, the Monster blows up the laboratory and the castle, killing Praetorius, the Bride, and himself.