Alp

The Alp (German: [alp]; plural Alpe or Alpen) is a distinctive supernatural entity in German folklore. While sometimes compared to vampires, its behavior more closely resembles that of the incubus. However, the Alp stands apart from both creatures through its defining characteristic—a magical hat called a Tarnkappe that serves as the source of its supernatural powers.

Etymologically, the word "Alp" shares origins with the English word "elf," both descending from Common Germanic. The creature appears under various regional names including trud, mar, mart, mahr, schrat, and walrider. Similar supernatural beings exist throughout European folklore, such as the Drude in nearby regions and the Old Hag in the British Isles—the latter now recognized as being connected to the sleep paralysis phenomenon.