Nurarihyon (aka Nūrihyon) and Umibōzu

Nurarihyon (ぬらりひょん^?), or Nūrihyon (ぬうりひょん^?), is a Japanese yōkai (a supernatural monster in folklore) said to originate from Wakayama Prefecture. It is also sometimes believed to be descended from the Umibōzu of Okayama Prefecture.

The Nurarihyon is usually depicted as an old man with a gourd-shaped head and wearing a kesa. He is sometimes said to be leader of the yōkai.

Nurarihyon is called the leader of the Hyakki Yakō.

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.

Umibōzu (海坊主^?, "sea bonze") is a spirit in Japanese folklore. The umibōzu is a very well known yōkai as it is also recognized in modern Japanese culture.

The Umibōzu is said to live in the ocean and capsize the ship of anyone who dares speak to it. This spirit's name, which combines the character for "sea" with the character of "Buddhist monk," is possibly related to the fact that the Umibōzu is said to have a large, round head, resembling the shaven heads of Buddhist monks. Alternatively they are enormous Yōkai (spectres) that appear to shipwreck victims and fishermen. They are believed to be drowned priests, and exhibit the shaven head and typically appears to be praying. It is usually reported as having a grey, cloud-like torso and serpentine limbs. According to one story, if angered, they ask that the crews provide a barrel that it proceeds to fill with sea water to drown them. To avoid this disastrous fate, it is necessary to give him a bottomless barrel.

Wakayama Prefecture (和歌山県 Wakayama-ken^?) is a prefecture of Japan located on the Kii Peninsula in the Kansai region on Honshū island.^[1]  

Okayama Prefecture (岡山県 Okayama-ken^?) is a prefecture of Japan located in the Chūgoku region on the island of Honshu.^[1]

In Japanese Buddhism, the kāṣāya is called kesa (Jp. 袈裟). Kāṣāya are the robes of Buddhist monks and nuns, named after a brown or saffron dye. In Japan, during the Edo and Meiji periods, kesa were even sometimes pieced together from robes used in Noh theatre.