Nurarihyon

Nurarihyon is a Japanese youkai, considered to be the leader of all youkai. He is usually depicted as an old man with a gourd-shaped head and wearing a kesa.

The Nurarihyon will sneak into someone's house while they are away, drink their tea, and act as if it is their own house. Because it looks human, anyone who sees him will mistake him for the owner of the house, making it very hard to expel him.