An obsessed scientist conducts profane experiments in evolution, eventually establishing himself as the self-styled demigod to a race of mutated, half-human abominations.
Tampering with life and death, Henry Frankenstein pieces together salvaged body parts to bring a human monster to life; the mad scientist's dreams are shattered by his creation's violent rage as the monster awakens to a world in which he is unwelcome.
Professor Frankenstein creates a teenager from an accident victim, who gets angry when he learns he is going to be taken apart.
A mad scientist creates a monster called "Mosaico," who breaks out of the laboratory to hunt down and kill beautiful women.
After a pawn shop robbery goes askew, two criminals take refuge at a remote farmhouse to try to let the heat die down, but find something much more menacing.
Confined to a mental hospital, young Kirsty Cotton insists her supposedly dead father is stuck in hell, controlled by sadomasochistic demons after being betrayed by his evil, occult-obsessed wife, Julia. Few believe Kirsty, except the thrill-seeking Dr. Channard, who is intrigued by the young woman's lurid stories. So when Kirsty and fellow patient Tiffany head to hell for a rescue, Channard and Julia are close behind.
After Malukan immigrants engage in a string of corpse mutilations at various New York City hospitals, a doctor and a morgue assistant travel to the Maluku Islands to investigate.
A brilliant but deranged neurosurgeon becomes obsessively fixated on a judge's daughter. With the help of an escaped criminal whose face he has surgically deformed, the mad man lures her, her father, and her fiancé to his isolated castle-like home, where he has created a torture chamber with the intent of torturing them for having 'tortured' him.
The eminent Dr. Phibes awakens from a decade of suspended animation and heads to Egypt with the corpse of his dead wife, which he intends to resurrect by murdering people in strange and heinous ways.
After a team of surgeons botches his beloved wife's operation, the distraught Dr. Phibes unleashes a score of Old-Testament atrocities on his enemies.
A fugitive, dangerous madman reaches an English village where he confronts his former partner who left him for dead in the jungle after their discovery of a diamond mine. When the former partner also claims to have since lost the mine and all its wealth, which he took all for himself, and though the partmer is still living in a state of luxury , the madman takes up an offer from a crazed scientist to make him invisible, something the scientist has already done with experimental animals, so that he can take revenge.
In 19th century England, a noted brain surgeon rescues a former student from being hanged on a false conviction for murder, and spirits him away to an ancient, repurposed abbey far in the countryside. There, he connives his pupil into assisting him in mapping the functions of the various parts of the human brain, using living subjects who are under a terrible animation-suspending drug called "black sleep". Subsequently, the student, along with the daughter of one of the subjects, discover that most of these subjects have survived but are being kept in a dungeon-like cellar, in various stages of physical and mental derangement...
An insane surgeon's obsession with an actress leads him to replace her wounded pianist husband's hands with the hands of a knife murderer--hands which still have the urge to throw knives.
A mad doctor (Bela Lugosi) and his helpers (John Carradine, George Zucco) lure girls to his lab for brain work, to help his wife.
An unnamed doctor has always had everything he's ever wanted, but that has only made him develop more extreme and depraved needs. He kidnaps a young couple in the prime of their life together and forces them into a game of torment that slowly extinguishes their hopes for survival.
A mad doctor uses patients at his isolated psychiatric institute as subjects in his attempts to create longevity by surgically installing an artificial gland in their skulls.
Murders, with victims dying from spines broken by brute strength, erupt in the city and the killers, when encountered, walk away unharmed by police bullets which strike them. A police doctor's investigation of the deaths leads to the discovery of an army of dead criminal musclemen restored to life, remotely controlled by a vengeful former crime boss and a former Nazi scientist, from the latter's laboratory hidden in the suburbs.
Dr. Henry Jekyll is a well-regarded physician whose evenings are spent researching a rare and sacred Amazonian flower so potent it's said to literally separate the soul, giving life to man's Dark Self. The obsessive experiments to isolate its psychotropic properties happen to coincide with a series of brutal murders gripping the city with fear. Jekyll knows it's no coincidence. While his nights are lost to him, he awakens with bloody mementos and violent memories of the screams of his victims.
Following his forced retirement from an appalling rock band, Jason decides to vacation at Brittlehouse Manor, a health farm run by the leather-gloved, ex-Nazi scientist Dr. Storm. Along the way, Jason meets Judy, also on her way to Brittlehouse Manor to visit her aunt, who married Dr. Storm some years ago. Once they arrive, the pair realise rather quickly that something is wrong, probably because the other guests have had their brains surgically removed, or all the blood pouring from the sink, or possibly just because the creepy midget keeps telling them to brush their teeth.
A scientist working on cures for rare afflictions, such as a bone softening agent made from molds to allow him to correct the spinal deformity of his nurse, finds the physical causes of lycanthropy in wolf-man Larry Talbot and of vampirism in Count Dracula, but himself becomes afflicted with homicidal madness while exchanging blood with Dracula.