is a yōkai from Japanese folklore that has the form of a giant, black, human-like being.

Little is known of the origin of umibōzu but it is a mythical sea-spirit creature and as such has multiple sightings throughout Japan. Normally, umibōzu appears to sailors on calm seas which quickly turn tumultuous. It either breaks the ship on emergence or demands a ladle from the sailors and proceeds to drown them. The only safe way to escape an umibōzu is to give it a bottomless ladle and sail away while it is confused.

The monster is known by other near-synonymous names such or .

Overview

They are often encountered by ships at night. A calm sea would suddenly surge and a giant black bōzu (bald-shaven) head surfaces, and destroy or damage ships. They are said to range from a few meters to tens of meters in length, but some are about human-size. It typically reveals only its upper body above the waist.

The umibōzu is not always solitary, and some lore claim that swarms of them arrive on ships to do mischief, such as clinging to the hull and scull as well as put out the basket fire. Their weakness is said to be smoke (tobacco fumes according to some) which causes them to flee.

The umibōzu is explained by some to be the ghost of the drowned, a belief held locally in Chiba Prefecture, though the lore from Chōshi, Chiba asserts that a certain priest named had drowned and became the umibōzu, according to Edo Period literature. (Cf. below). An English source claims the umibōzu is more generally regarded as the spirit of the drowned priest.

The lore of the umibōzu is widespread and occurs all over Japan. Also the story of the umibōzu (or some maritime yōkai under various names) that asks for a ladle-type utensil then tries to sink the gift-giver's ship by scooping water in it, is found all over Japan.

In a commonplace story, the umibōzu asks for a ladle-type utensil from the gullible seafarer, only to have the creature try to fill the ship with the implement and try to sink it. In the version of Ukujima island (of the Gotō Islands, Nagasaki Prefecture), the creature is called either umibōzu or funayūrei, and demands a hishaku (wooden dipper). Since it would try to use it to pour water into the fisherman's vessel, the wise strategy to survive this is to lend a ladle with the bottom punched out. This story is found all over Japan, though the sea creature may be told under various names. which is presumably a ladle or dipper also. In the version of , Aichi, the funayūrei demands an aka-tori ()、where aka refers to "bilge water" and tori means "taker, gatherer" for any kind of such tool.From the History of Minamichita 南知多町誌, cited in via , cognate accounts: , International Research Center for Japanese Studies..

Nomenclature Other (near-synonymous) names include or , where (literally "law-master") and both refer to a monk or priest.

The umibōzu has a clean shaven head like a priest's, as aforementioned. Some English sources also generalize the umibōzu to be the spirits of drowned priests.

Sometimes the umibōzu is conflated with the , and it is difficult to make a stark distinction between them. As in the aforementioned example the same yōkai may be known as either funayūrei or umibōzu (Gotō Islands).

In the western seas the creature known as umibōzu is a human-headed sea turtle, corresponding to the (or in Japanese, meaning "monk-fish") from Chinese literature (cf. )

In European folklore, there is also said to be sea creatures of like meaning, namely the sea monk and sea bishop.

Legends by area

Kyūshū region In the aforementioned lore around northern Gotō Archipelago, the part about the umibōzu aka funayūrei demanding the ladle is a motif that is widespread throughout Japan as aforementioned, but there are more superstitions about this yōkai according to fishermen of the area, namely, that it never tries to come aboard ship from the aft (stern) of the ship because the faces that way, and always tries to climb from the prow. Also, if it clings onto the scull (oar), then one should keep pushing it until the edge of the oar digs in, and the umibōzu would start screaming " (ouch ouch)" in pain..

Skikoku region

In Uwajima, Ehime Prefecture, there are tales where they would shapeshift into a zatō (blind person) and kill human women. Also, while there are many legends of them attacking humans, in Uwajima there is the legend that those who see an umibōzu would live a long life.

Chūgoku region In Nagato Province (now Yamaguchi Prefecture), at a part of village called Kawashiri, there is a tale passed down about a fisherman long ago who had been out night-fishing and witnessed a umibōzu that came to extinguish the basket fire, so he threw the fire-lit torches at the monster.

In the Sea in-between Okayama Prefecture and Kagawa Prefecture, tales are told of a type of umibōzu called the nurarihyon with a large round head: they float towards the boat, and slowly (nurari) away and then unexpectedly (hyon) float approaching the boat again. They would do this several times over to taunt people. This marine creature is completely different from the old man-like yōkai called nurarihyon that bears the same name.

Around the San'in region it is said that one can encounter the umibōzu on the shore as well, while walking on the beach at night, and the slick, black mass-like creature will rub itself onto the passerby and attempt to drag the person into the sea. There are anecdotes of some survivor who got away with all his might.

From Tottori Prefecture, a piece of writing from the Edo period called attests to the umibōzu. A strong man from the village next to (now part of Matsue) who boasted of being undefeated in sumo matches held at ceremonies encountered the one-eyed monster shaped like a stake measuring 2 shaku () circumference. The man captured the monster after a struggle. Most villagers who gathered could not identify it, but a 90-year old man suggested this might be the umibōzu, said to lean on to people it finds, with its body slick with goo, causing an itch all over the body if touched, or so the old man had been told by his grandfather long ago.。

Kinki region There is also the umibōzu of unusual appearance. The creature was said to appear periodically in the bay of (now Kemi in Wakayama city, Wakayama Prefecture). Finally, one was caught in the area at Miidera town, as reported in the 26 December 1888 issue of the Miyako Shinbun of Tokyo. This umibōzu was about tall and weighing about 60–70 kan (), and was a large ape-like creature with brown hair, orange eyes, a mouth of a crocodile, belly of a fish, tail of a lobster, and the cry of a bull.

On Awaji Island in town of (now part of Sumoto, Hyōgo Prefecture), it has been told that one can be spared from an umbōzus attack by tossing the most precious cargo into the sea. However, the prescribed rule demands one must jettison the objects from the bow end of the boat.

Tohoku region In the Tohoku region, there is a custom of making an offering of the first catch of the season (hatsumono) to the Sea God, and if this is disregarded, the umibōzu was said to appear and destroy the boat and kidnap the boat owner.

Umibōzu are also said to change their appearance, and a tale is told on the island of in Kesennuma, Miyagi Prefecture, about an umibōzu that shapeshifted into beautiful women and engaging in swimming contests with humans. There is also a similar tale in Iwate Prefecture, but there it is said that those who accept the challenge would be swallowed down instantly.

Chūbu region In land-locked Nagano Prefecture there is no sea coast, but still claims to have umibōzu dwelling in its rivers. According to legend, it lived in rivers near Kaesa in Nakano city, had giant body and a black head like the head of a giant Buddha statue. Only its upper body was said to show above water..

Ship ghosts and ghost ships In Cape Shiriya, Higashidōri, Shimokita District, Aomori Prefecture, it is said that people eaten by sharks would become . These ghost ships can be repelled by dissolving some miso (soy bean paste) in water and letting the cold soup flow down the sea.

Similar creatures The "umikozō" told about in the Kamo District, Shizuoka Prefecture is a boy covered with hair all the way to the sides of the eye, and it is said that they would approach fishing lines with a grin.

The folklore of the frightening or (from literally "Mongol and Kogureo Korea"), presumably the ghosts of the victims of the Mongol invasion is passed on in various ways, but in the area of Tanabe, Wakayama Prefecture it is told that the monster[s] appear when people visit the mountains on the lunar March 3 or if people visit the sea on the lunar May 5. According to one local informant, the ones that appear in the sea are a swarm of jelly-fish like things. Thus this has been characterizable as an umibōzu of a sort. But locals tell it differently for the mokuri kokuri that appears on land, namely, that they are human-like creatures that stretch or shrink to different size, and are encountered in the wheat fields. And according to a variant told at Kamikohama beach in Tanabe, the terrestrial mokuri kokuri is a weasel-like small beast that puncture the butts of humans who enter wheat fields at night.Kyōdo kenkyū 郷土研究 3(1)–(3), March–May 1913, , recapped by . This version is conjectured to be a conflation of the lores of the "earth-rat" (i.e. mole) and the kappa by Minakata Kumagusu

In the Kitauwa District, Ehime Prefecture, the sea would become white at night and a "shirami", also called "shirami yūren", would come swimming, and fishers would call these idiots. However, it is said that if they hear "idiot", they'd get angry and cling on to the scull and give a bad time.

On Sado Island, the "tate-eboshi" ( "propped up hat") is a monster said to stand at a height of who would aim at ships and try to flip them over.

In classical literature

The (published 1687) includes a narrative claiming an encounter with a -type umibōzu, which purportedly took place during the Meiō era (1492–1501). Two sarugaku performers, a drummer and a flautist, needed passage to Suruga Province and boarded a ferry boat from Ise Province (Mie Prefecture) bound for Cape Irago (Aichi Prefecture). The ferryman had the policy of refusing a "lone woman" aboard, but the drummer or insisted his wife be carried. When the boat encountered a big storm, the ferryman angrily blamed the presence of the lone woman for incurring the anger of the Dragon God, and told the group to cast valuables into the sea to appease the god, to no avail, Then the black bald thing appeared, which had a head five to six times the size of a human's, glittering eyes as large as Tenmoku teacups, and a horse-like (or bird-like) mouth that was in length. The wife made her resolve and tossed herself into the ocean, and the black bald thing snatched the woman in its jaws, upon which the waves calmed and the group made it ashore, though bereft of their possessions. According to the ferryman, the black bald thing was a monster called . These umibōzu are said to be fallen dragon deities who would demand sacrifice.

According to the narrative found in the , the samurai (d. 1441) was crossing the sea to Tsushima he had an encounter with a slick, oily sea monster, and asked about it from a local fisherman, who replied that such monsters exist, additionally informing the warrior that the sea also has creatures called the (or measuring in height, and had neither eyes, nor nose, nor limbs. Upon seeing one, it was considered necessary to say nothing and pretend to have seen nothing, because if one says even something such as "what was that?" it would sink the boat in an instant.