Colossal Yokai

Gashadokuro is a yokai in the form of a giant skeleton, said to be formed from the assembled bones and grudges of countless dead who perished from war or starvation and were never properly buried, gathering together in the deep darkness of the night. It wanders through night fields and wastelands, and when it finds a living human, it catches them with its giant bony arms, crushes their head in its jaws, and drinks their blood. The name is said to come from the eerie "gasha gasha" rattling sound its giant bones make rubbing against each other as it walks. However, when examining this yokai from the perspectives of folklore and yokai studies, we arrive at a highly shocking fact. Gashadokuro "does not appear at all" in classic Japanese ghost stories or folklore prior to the Edo period. No matter which region's traditions in Japan one traces back, no record of this yokai can be found. In truth, the Gashadokuro is a "modern fictional yokai (invented tradition)" created entirely from scratch by writers of children's horror books during the "yokai boom" of the mid-Showa period (late 1960s). The history of its creation suggests that its first appearance was in 1966, when occult writer Morihiro Saito coined the name "Gashadokuro" and established its basic concept, drawing inspiration from Western ghost tales (such as headless phantom knights), and published it in a magazine for boys and girls. Then, to give this entirely new concept overwhelming visual persuasiveness, what was "borrowed" later was the illustration of a giant skeleton from the masterpiece ukiyo-e print "Takiyasha the Witch and the Skeleton Spectre" (Soma no Furudairi) (circa 1845) by the genius ukiyo-e artist of the late Edo period, Utagawa Kuniyoshi. Kuniyoshi's ukiyo-e was originally based on the yomihon "Zenthi Yasutaka Chugiden" by Santo Kyoden, depicting the scene where Princess Takiyasha, daughter of Taira no Masakado, uses sorcery to unleash a skeleton upon Oya Taro Mitsukuni. In the original book's description, "hundreds of life-sized skeletons appear," but Kuniyoshi employed his uniquely dynamic sense of composition to boldly arrange the countless skeletons into "a single giant skeleton." In other words, what Kuniyoshi drew was strictly "a giant bone monster summoned by Princess Takiyasha's sorcery," and absolutely not the yokai known as "Gashadokuro" born from gathered grudges. However, in the 1970s, in Arifumi Sato's "Illustrated Encyclopedia of Japanese Yokai" (1972) and Shigeru Mizuki's yokai illustrations, the name and concept invented by Saito were perfectly combined with the visual of Kuniyoshi's terrifying giant skeleton. As a result, the historical illusion (fake lore) of an "ancient, terrifying yokai depicted even in ukiyo-e" was brilliantly completed, and the Gashadokuro instantly took deep root in the minds of children and adults across Japan as a "traditional Japanese yokai."

Umibōzu is a sea-dwelling yokai feared by coastal communities across Japan, especially among fishers. It appears as a vast black mass or a bald monk-like head rising from the waves, often seen as a harbinger of shipwrecks and maritime disaster. Its full body is rarely visible; most accounts describe only a head and shoulders jutting above the surface. Said to emerge at night or in storms, it overturns boats or drags sailors into the depths.

The Seven-Fathom Wife is a giant female yokai from eastern Shimane (Izumo), the Oki Islands, and Hōki in Tottori. The term “fathom” (hiro) is a unit of length, and her height—or in some tales her neck—reaches seven hiro. She appears on mountain paths or along the shore, smiling at travelers, throwing stones, or miming laundry to bewilder people. Her look and behavior vary by locale, ranging from a beggar of striking beauty to a fearsome woman with blackened teeth and disheveled hair.

The Sandworm does not appear in any classical Japanese yokai picture scrolls or folktales; it is, so to speak, a "modern imported yokai." It is known as a giant worm monster that digs through the underground of deserts and sand dunes at breakneck speed, swallowing prey whole along with the sand using its massive, cylindrical mouth. Its direct origin is definitively traced to the Sandworms (Shai-Hulud) appearing in Frank Herbert's 1965 monumental sci-fi novel *Dune*. However, since the 1980s, its recognition exploded in Japan through fantasy RPGs like *Final Fantasy*. It has completely taken root among Japanese youth as a shared terrifying experience (a kind of modern folklore) as "the most terrifying monster that surely lurks in the harsh environment of a desert," making it an anomaly with an extremely unique history of reception.

Ushioni (牛鬼) is a highly ferocious yokai with immense spiritual status, primarily said to appear on the coasts, in deep pools, and in the mountainous regions of western Japan. Its appearance is depicted in various grotesque forms, such as "a demon's body with a cow's head" or "a spider's body with a cow's head." Long ago, it was singled out as a "terrifying thing" in the Heian-period *The Pillow Book* (Makura no Sōshi), and has been deeply feared by people since ancient times. Its true nature lies in its extreme duality (the two-sidedness of good and evil): on one hand, it is a "cruel evil demon and god of plague" that indiscriminately devours humans and scatters poisonous miasma; on the other hand, it acts as a "powerful guardian deity" that leads portable shrines in festivals to exorcise evil spirits. It is an extremely important yokai in folklore studies, having evolved from a supernatural anomaly in literature to an object of regional folk belief and performing arts.

A colossal catfish believed to lurk underground, twisting its body to cause earthquakes. Earlier notions held that dragons or serpents beneath the earth triggered quakes, but by the Edo period the agent shifted in popular belief to a catfish. Faith spread that the keystones (kaname-ishi) of Kashima and Katori shrines pinned the creature in place. After the 1855 Ansei earthquake, woodblock “catfish prints” (namazu-e) proliferated, turning the catfish into an emblem of quake protection and social upheaval.

Kuzuryū is told as a dragon with nine heads, venerated across Japan as a water deity and a bringer of rain. In Togakushi, legend says it cast off its demonic nature through the power of ascetic rites and became a benevolent water god, enshrined as Kuzuryū Ōgami. In Echizen, it is linked with black- and white-dragon cults and the origin tales of the Kuzuryū River, serving as a guardian deity invoked for flood control and national well-being in connection with the cult of Hakusan Gongen.

Ōnyūdō is a giant, priest-like apparition—and sometimes a towering shadow figure—reported across Japan. The name means “great monk,” yet it does not always appear in clerical form; accounts describe colossal humanoids or amorphous shadows looming overhead. Its glare is said to make onlookers faint or fall ill. While its true nature is often left unstated, some traditions claim it is a transformed animal—fox, tanuki, weasel, or otter—or even a bewitched stone stupa.

The Giant Centipede is a monstrous centipede yokai whose carapace is so hard it deflects blades and arrows. Its body is long enough to coil around mountains, its many legs glow a fiery red, and its venomous fangs were said to bite through armor. It is portrayed as an adversary of great serpents and dragons—water deities—with whom it battles in lakes, marshes, and the wilds. Centipedes symbolized fearless resolve and were seen as auspicious by warriors and merchants, though details of this creature vary widely by region.

The Great Spider is a spider that has lived long enough to gain supernatural power, troubling people and monks. It hides in the mountains or in temple rafters, brushes people’s faces late at night, and drains their vitality, causing illness. It may take human form—often as an old woman—and ensnare victims with silk. References appear in records and essays; it may also be called “mountain spider” or “tsuchigumo,” though details and abilities vary by region.

A bizarre apparition in which an enormous woman’s head appears in the sky or at a house’s doorway. It is often shown with ohaguro—blackened teeth—suggesting a married woman. Toriyama Sekien included an image in his mid-Edo Konjaku Gazu Zoku Hyakki, where the head drifts in a rainy night sky. While Sekien’s rendering is considered satirical, anecdotes and essays from many regions report encounters with giant female heads, interpreted as vengeful spirits, lingering grudges, or foxes and badgers in disguise.

Ōmagatoki refers to the dim hour when day slips into night—the period overlapping with twilight. It’s the in-between time when faces are hard to make out and people are thought to be most likely to encounter demons or yokai. Parents warned children to stay indoors then. The Edo artist Toriyama Sekien glossed it as “the hour when a hundred specters arise,” and folklorist Yanagita Kunio noted older meanings tied to vigilance against shapeshifters. Local dialects preserve related terms with similar nuances.

Yamata no Orochi is the enormous serpent deity of Izumo mythology, recorded in the Kojiki, upper volume, completed in 712 and the Nihon Shoki, book one, section eight, completed in 720. It is said to have lived in the upper reaches of the Hii River, anciently called the Hi River, and to have been slain by Susanoo. Yet Orochi is not simply a monster to be defeated. It can be read as the spirit of Izumo's mountains and rivers, the memory of a flooding river, a mythic image of sand iron and tatara ironmaking, and a sign of local Izumo cults being drawn into the mythology of Yamato rule. The Kojiki describes eyes red like winter cherries, one body with eight heads and eight tails, moss, cypress, and cedar growing on its back, a body stretching across eight valleys and eight ridges, and a belly always bloody and raw. Susanoo prepares eight vats of strong yashiori sake and an eightfold fence, lets the eight heads drink themselves senseless, cuts the serpent down with his totsuka sword, and finds the great sword Tsumugari in the middle tail: the later Kusanagi, or Ame-no-Murakumo. This sword becomes the martial treasure among the Three Sacred Treasures. After the victory, Susanoo marries Kushinada-hime, builds a palace at Suga in Izumo, and composes the celebrated "Yakumo tatsu" poem, often treated as Japan's earliest waka. Today Unnan records roughly fifty sites tied to the Orochi legend, while the Iwami Kagura drama Orochi keeps the serpent on stage in the present.

The Great Zato is a yokai depiction of a blind guildsman (zato) illustrated by Toriyama Sekien in Konjaku Hyakki Shūi. Wearing tattered hakama, wooden clogs, and leaning on a staff, it roams the main roads on stormy nights. When questioned, it replies that it “always plays the shamisen at brothels.” The image caricatures the nighttime presence of professional blind performers, blending otherness and social satire into a yokai form.

Ootakemaru is a demon god said to have made his stronghold at Mount Suzuka and the Suzuka Pass, located on the border between Ise and Omi provinces. In Otogizoshi and the Tamura stories, he appears as a Great Demon King who steals tributes meant for the capital and repels armies with black clouds, lightning, and rain of fire, only to be slain by Tamuramaru (modeled after Sakanoue no Tamuramaro) and Suzuka Gozen. The Tamuramaru of the story is not the historical Shogun himself, but a heroic figure born from the overlapping of medieval Kiyomizu Kannon worship, boundary beliefs of the Suzuka Pass, and Tamura legends from the Tohoku region. Ootakemaru is also sometimes cited as one of the "Three Great Yokai" alongside Shuten-doji and Tamamo-no-Mae. The fact that his severed head and remains are later incorporated into tales of treasures, temple origins (engi), and burial mounds reflects the medieval significance of a "slain great enemy".

A shape-shifting tanuki specter from Keida in Mishō Village, Miyoshi District, Tokushima. It appears when boats anchor late at night at the Aoiseki (Blue-Stone Rapid) on the Yoshino River, extending an enormous kiseru pipe and demanding tobacco. If you can pack the pipe full, it causes no harm—but the amount required is absurdly large. If your supply runs out, it capsizes the boat or triggers strange disturbances. It is a waterside tanuki that frightens travelers and boatmen, told as a cautionary tale.

A notorious ogre chieftain who abducted people around the Heian capital. Fond of heavy drinking, he led a band of oni from a mountain stronghold to raid travelers. His name alludes to his love of sake, while dōji refers to a youth or monk-like appearance. Slain by Minamoto no Raikō and his Four Heavenly Kings, his severed head was said to bite even after decapitation. His lair is variously placed at Mt. Ōe, Mt. Ibuki, or Mt. Atago, supposedly located through onmyōji divination.