Umi Bozu

Umi bozu is a yokai sea spirit from Japanese folklore. They appear on calm nights as a large humanoid shape emerging from the water, causing sudden turbulence and wild waves. Umi bozu will attempt to sink ships by demanding a barrel from the crew and then proceeding to scoop water into the boat. The only way to escape is by throwing them a bottomless barrel and quickly escaping while it's confused. Some believe umi bozu is the spirit of a monk who drowned at sea.

The Sea Monk, Utagawa Kuniyoshi, 1843

Shigeru Mizuki