Nightmare Creatures is a 1997 survival horror video game developed by Kalisto Entertainment for Nintendo 64.

The story behind Nightmare Creatures draws upon gothic horror elements of the 19th century and begins in 1666, when a devil-worshiping cult called the Brotherhood of Hecate were conducting sinister experiments in London so as to take over the city, and then the world. The Brotherhood tried to develop an elixir that would endow them with superhuman powers. However, rather than creating their intended superhumans, their experiments instead created grotesque monsters called nightmare creatures. When they decided to use these creatures as an army of conquest, one of their members, Samuel Pepys, set their headquarters on fire, resulting in the First Great Fire of London.

The game takes place in 1834 when London falls victim to several evil occurrences. Monster sightings are reported along with news of people mutating into ungodly creatures, and that the dead are waking from their graves and walking among the living. All of London is in a panic and vulnerable to the schemes of Adam Crowley, a mad scientist and occultist enlisting the help of the Brotherhood.