List of creatures that pretend to be human

Changeling - European - Troll, faerie and elf children who were switched at birth for various reasons.
The Devil - various - Believed to take on human forms in order to tempt people
Doppelgänger - German - A ghostly double of a living person
Ghoul - Arabic - Harmful jinn who like human flesh. They can make all but their feet look human to lure the unwary.
Kitsune - Japanese - Foxes who can take the form of beautiful maidens. A kitsune was said to be the mother of the legendary onmyoji Abe no Seimei.
Noppera-bō - Japanese - Sometimes also called a mujina, At first appearing completely human, when approached they are able to wipe their face completely off, as though cleaning a chalkboard, leaving behind a featureless orb similar to an egg. Was first introduced to the west by writer Lafcadio Hearn in his 1903 novel Kwaidan: Stories and Studies of Strange Things.
Selkie - Scottish - Seals who can shed their skins to become beautiful maidens
Tanuki - Japanese - Raccoon dogs who can take the form of people, though it is not always a perfect transformation.