Alp

An alp is a nightmare creature originating from Teutonic or German folklore.

Not to be mistaken with the similarly named Alp Luachra, the alp is sometimes likened to a vampire, but its behavior is more like that of the incubus. The word "alp" is also a variation on the word "elf", and it also is known by the following names: trud, mare, mart, mahr, Schrat, and Walrider. Many other variations exist in surrounding European areas. The appearance of the alp itself is rarely described, other than it wears a hat and can shape-shift.