An insane scientist doing experimentation in glandular research becomes obsessed with transforming a female gorilla into a human...even though it costs human life.
Grave robbers open the grave of the wolf man and awaken him. He doesn't like the idea of being immortal and killing people when the moon is full so tries to find Dr. Frankenstein, in the hopes that the doctor can cure him. Dr. Frankenstein has died; however, his monster is found.
A Serbian émigré in Manhattan believes that, because of an ancient curse, any physical intimacy with the man she loves will turn her into a feline predator.
A high priest of Karnak travels to America with the living mummy Kharis (Lon Chaney Jr.) to kill all those who had desecrated the tomb of the Egyptian princess Ananka thirty years earlier.
England, at the start of World War Two. Mysterious wireless broadcasts, apparently from Nazi Germany are heard over the BBC. They warn of acts of terror in England, just before they take place. Baffled, the Defense Committee call in Sherlock Holmes.
Frankenstein's unscrupulous colleague, Dr. Bohmer, plans to transplant Ygor's brain so he can rule the world using the monster's body, but the plan goes sour when he turns malevolent and goes on a rampage.
After his brother's death, Larry Talbot returns home to his father and the family estate. Events soon take a turn for the worse when Larry is bitten by a werewolf.
Dr. Jekyll believes good and evil exist in everyone and creates a potion that allows his evil side, Mr. Hyde, to come to the fore. He faces horrible consequences when he lets his dark side run amok.
A down-on-his luck businessman organizes an excursion to Sir Henry Morgan's Island for a treasure hunt only to encounter a mysterious phantom and murder.
After a young woman is coerced into prostitution and her brother framed for murder by an organized crime syndicate, retribution in the form of an ape visits the mobsters.
Kitty Carroll, an attractive store model, volunteers to become a test subject for a machine that will make her invisible so that she can use her invisibility to exact revenge on her ex-boss.
Dr. Paul Carruthers is frustrated because he thinks his employers, Mary Heath and Henry Morton, have cheated him out of the company's profits. He decides to get revenge by altering bats to grow twice their normal size and training them to attack when they smell a perfume of his own making. He mixes the perfume into a lotion, which he offers as a gift to Mary and Henry. When they turn up dead, a newspaper reporter decides to investigate.
A couple of young, out-of-work archaeologists in Egypt discover evidence of the burial place of the ancient Egyptian princess Ananka. After receiving funding from an eccentric magician and his beautiful daughter, they set out into the desert only to be terrorized by a sinister high priest and the living mummy Kharis who are the guardians of Ananka’s tomb.
Dr. John Garth conducting an innovative medical experiment aimed at prolonging life and combating aging. The experiment takes an unexpected turn, placing the doctor in a confrontation with the ethics of his work and the consequences of his research.