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Beasts of Belief (#1): Yōkai Spirits of Japanese Folklore

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Curatorial and outreach assistant Jake Gentry unleashes a horde of Japanese Yōkai in this first installment of the Beasts of Belief blog series!

Japanese folklore is well-known for its supernatural creatures, especially its spirits, which come in a myriad of forms and temperaments. Yōkai (妖怪) are a classification of spirits described by Michael Dylan Foster as a “monster, spirit, goblin, ghost, demon, phantom, specter, fantastic being, lower-order deity, or, more amorphously, as any unexplainable experience or numinous occurrence” (2). Animism, the belief that all things possess a unique spiritual energy or essence, is common in multiple faith systems in East Asia. Some notable examples include Shinto, which revolves around the worship of kami (神), hidden spirits that inhabit places, ideas, and natural phenomena, and Ryukyuan religion (the indigenous religion of the Ryukyu Islands), which includes the belief in mabui (まぶい), or life essence, and the worship of ancestral and natural spirits. In any case, yōkai sit at an intriguing intersection between religion, superstition, and sociocultural belief. The sheer amount of these wonderfully strange and occasionally terrifying spirits is staggering; thus, I have selected for you a spooky sampling of some of the Lilly Library’s favorites!

YŌKAI #1: BAKU (貘)

  • NAME MEANING(S): “Tapir” (as in the Malayan tapir or Tapirus indicus)
  • HABITAT: Deep in thick forests (Meyer), mountains
  • DIET: Nightmares, hopes and desires (occasionally)
  • DANGER LEVEL: Moderate, may eat your dreams
  • LILLY LIBRARY APPEARANCES: NE1325 .T12

A chimerical dreamcatcher/dream-caretaker, the baku (貘) is a mythical creature that originated from Chinese mythology before being adopted into Japanese folklore. Known originally In China as the Mo (a now obsolete name for the giant panda, or Ailuropoda melanoleuca), it was described as a timid beast with an elephant’s trunk and tusks, a tiger’s paws, an ox’s tail, a rhinoceros’s eyes and ears, and a spotted, black and yellow body of a bear (Nakagawa). Noticeably, as the Mo, this beast did not consume dreams but rather had a strict diet of copper and iron, and was known to repel pestilence. The baku’s confusing form stems from the legend that it was created from the leftovers of other animals when the gods were finished making all living things– a trait that makes it holy in some circles. We love an underdog.

Image of a Japanese woodblock print of two chimerical creatures flying in the air, with elephant-like noses, horns, claws, and spots. They float over a swirling stream.
Woodblock relief print of two baku circling one another, from Tachibana Morikuni’s (橘守国) Ehon tsūhōshi (NE1325 .T12), published in Osaka, Japan in 1721. Note the symbol for baku or tapir (貘) in the upper right corner, which has become a good luck talisman meant to ward off nightmares and evil spirits.

In Japan, as early as the Muromachi period (1336-1573), the baku had shed its shy demeanor and became depicted as a fierce protector of mankind, one that fed on nightmares rather than metals. As guardian spirits, the presence of a baku was known to repulse evil spirits and yōkai, who avoided baku-inhabited areas. Evil’s aversion to baku allowed good luck and health to flourish wherever they were found (Meyer). This, in turn, imbued baku and their symbol with protective properties– with the kanji for baku being used for good luck talismans and even sewn onto pillows to defend against nightmares. It was common for Japanese children in the 1910s to keep a baku talisman close when they slept, and if they suffered from a nightmare, uttering the phrase “Baku-san, come eat my dream” thrice could summon a baku to devour their bad dreams (Davis). There was caution to be had when summoning a baku, however. If the beast was not satiated after consuming your nightmare, it may also eat your hopes and dreams, dooming you to a hollow life (Yikes!). Notably, baku are also featured in religious architecture, seen atop columns and roofs of Japanese temples to ward off evil spirits, akin to the Western gargoyle. Baku are among a select few creatures deemed holy enough for such an honor (Meyer). In modern-day, the tapir-like dream-eater has hit a resurgence, and has since appeared in Japanese anime and manga.

YŌKAI #2: HITODAMA (人魂)

  • NAME MEANING(S): “human soul”
  • HABITAT: Graveyards, funeral parlors, near the recently deceased (Meyer)
  • DIET: None
  • DANGER LEVEL: Harmless
  • LILLY LIBRARY APPEARANCES: NC991.T68 K8 v.1-3
Woodblock relief print of a ghostly blob leaving a house through a window.
Woodblock relief print of a hitodama leaving a house, its distinctive wispy tail drifting behind it. This illustration comes from the Konjaku zoku hyakki (NC991.T68 K8 v.1-3) by Toriyama Sekien (鳥山 石燕). Sekien, whose real name was Sano Toyofusa, was a Japanese scholar, kyōka poet, and ukiyo-e artist. (I particularly love this depiction because this hitodama looks like a cute little speech bubble!!)

A hitodama (人魂) is a phosphorescent ball or blob of ghostly fire. Spiritual manifestations of the deceased, they emanate or linger around corpses. Known to float in the air and near the ground at night (and very rarely, sometimes during the day), they come in a variety of colors, ranging from orange, red, or blueish white. They always possess a tendril-like tail of light, which can be short or long, depending on the depiction. The legend of the hitodama is quite old, as they are referenced in the Man’yōshū (万葉集); meaning “Collection of Ten Thousand Leaves”), which is the oldest extant collection of Classical Japanese poetry– waka— compiled sometime during the Nara period (specifically between the years 759-794 AD). In the Man’yōshū, a verse reads: That rainy night, when all alone/ I met you with your face ghastly pale/ Like a spectral fire (Chapter 16). Another translation of this verse reads “When you are alone and meet the complete blueness of a hitodama…” (Man’yōshū 77-78).

These spectral orbs are usually seen right before or after someone dies, when the soul is said to leave the body (Meyer). Rarely, hitodama have also manifested from a living person who has lost consciousness, with the spirit orb returning when their body wakes (Meyer). While hitodama are harmless, they closely resemble multiple fireball yōkai that decidedly are not, such as onibi (鬼火; “Demon Fire”) and kitsunebi (狐火; “Fox Fire”). Theories abound on what hitodama may be based on– an interesting idea proposes that their frequency on warm summer nights suggests that hitodama come from ancient encounters with fireflies (known as hotaru in Japanese). Other theories point to plasma, swamp gas, and even shooting stars!

Fun fact(s): Japan has three native species of fireflies: Luciola cruciata, Luciola lateralis, and Colophotia praeusta, as well as a firefly-catching festival held annually in Fusa-park in Tokyo called Hotarugari (蛍狩り), which means “firefly catching.”

Japanese woodcut relief print of a field with a ghostly fireball floating in the air.
Woodblock relief print of a chochinbi (提灯火; “Lantern Fire”), a type of onibi that haunts the footpaths of rice fields, where they appear in long rows close to the ground, mimicking strings of lanterns. They snuff themselves out when people approach them, stranding their followers in darkness. They deceptively manifest at the same height and brightness of a handheld paper lantern (known as a chōchin (提灯), which they are named after (Meyer). Be wary of the chōchinbi, as seeing them means other yōkai are near, who use them to light their way. These eerie lights are commonly associated with and even created by other spirits, such as kitsune (狐). Note the fox-like figure that is creating the chochinbi in the illustration, which is from Toriyama Sekien’s Konjaku zoku hyakki (NC991.T68 K8 v.1-3).
Image of an illustration of a nine-tailed fox, a kitsune from Japanese mythology.
Hand-painted illustration of a kitsune (狐), a nine-tailed fox yōkai known for their intelligence, mischief, and magical powers, which include shape-shifting, longevity, and igniting of chochinbi (提灯火; “Lantern Fire”) and kitsunebi (狐火; “Fox Fire”). Like most yōkai, the kitsune comes from the transformation of something ordinary. In this case, when a fox reaches a hundred years of age, it becomes a kitsune and gains a new tail every century it lives, reaching up to nine tails (therefore, our foxy friend in the illustration is at least 900 years old!). This illustration is from Shinji andon (NC991 .S556 v.1-4), published by Eirakuya Tōshirō in Nagoya between 1829-1847. Fun fact: “kitsune” is the Japanese word for fox!

YŌKAI #3: NOBUSUMA (野衾)

  • NAME MEANING(S): “field bedding” or “wild quilt”
  • HABITAT: Mountains and mountainous forests
  • DIET: Blood (primarily), fruits, nuts, fire
  • DANGER LEVEL: High!
  • LILLY LIBRARY APPEARANCES: NC991.T68 K8 v.1-3
Image of a Japanese woodblock print featuring a flying-squirrel-like creature pursuing two birds in the air. They fly over a stream with a small waterfall.
Woodblock relief print of a nobusuma (野衾; “field bedding”) pursuing two birds, from Toriyama Sekien’s Konjaku zoku hyakki (NC991.T68 K8 v.1-3). The nobusuma most likely earned its name from its fur and webbed wings, which make it appear as a small blanket when in flight (Sekien 137). How cute, for a vampiric facehugger-flying-squirrel spirit.

Adorable yet fearsome, the nobusuma (野衾; “field bedding”) proves that when it comes to yōkai, size does not always correlate with threat level. Depicted as a furry, flying squirrel or bat-like creature with webbed wings, four short limbs, and long, sharp claws, the nobusuma is equated as the supernatural counterpart of Petaurista leucogenys— otherwise known as the Japanese giant flying squirrel (ムササビ, musasabi), which also eats fruit and nuts (Sekien et al. 137). Most likely, the legend of the nobusuma stems from encounters with the nocturnal musasabi, which leave their homes in hollow trees at night and glide through the air in search of food. Their night vision could easily be impaired by the bright light shed by torches or lanterns, resulting in them colliding with travelers. This connection to a real-world creature is furthered by the transformative nature of yōkai, with legend stating that long-lived bats metamorphose into nobusuma when they reach a certain age (Meyer).

The nobusuma has two distinct behaviors, both of which are predatory. The first is consuming the fire of torches carried by travelers, leaving them in the dark and unable to navigate the night (not unlike other yokai, like the hikeshi baba (火消婆; “fire extinguishing old woman”). After they swoop down and chomp on torches, they will vanish back into the night with a bat-like “gaa gaa!” cry (Meyer).

The nobusuma’s other known hobby is much more horrifying and directly harmful to its prey: attacking from the air, it will latch onto its victim’s face, using its forepaws and wings to gag and bling them before sucking on their blood (in like manner to the lovely little facehugger from Ridley Scott’s Alien). They are known to feed on the blood of small animals too– in 1798, the Baiō zuihitsu (梅翁随筆; zuihitsu means “following the brush”), an Edo-period publication, claimed that nobusuma from high in the mountains were preying on cats. (Not cool, nobusuma. I’m calling PETA.)

Image of a ghostly female spirit blowing out a lantern with an blast of air.
Woodcut relief print of a hikeshi baba (火消婆; “fire extinguishing old woman”), depicted in Toriyama Sekien’s Konjaku zoku hyakki (NC991.T68 K8 v.1-3) as a white-haired, monstrous hag. Like the nobusuma, the hikeshi baba is known to snuff out sources of light– she wanders from home to home, blowing out lanterns (Meyer). While the hikeshi baba is not dangerous itself, the act of extinguishing lanterns and dimming homes is, as she provides the darkness needed for more dangerous yōkai to creep in.

YŌKAI #4: SHINKIRŌ (蜃気楼)

  • NAME MEANING(S): “mirage” or “clam breath tower”
  • HABITAT: Open oceans (Meyer)
  • DIET: None
  • DANGER LEVEL: Harmless
  • LILLY LIBRARY APPEARANCES: TX747 .S45 1849, PL801.K8 M61 2013
Image of a Japanese woodblock print depicting a clam releasing a stream of vapor.
Two-page woodblock relief print depicting shen clams breathing out shinkirō mirages of illusionary cities, from Seitaien’s Gyokai nōdoku hinbutsu zukō (TX747 .S45 1849), which was published in Edo (modern-day Tokyo) in 1849 by Suharaya Mohee. The kanji in the upper right corner reads “shinkirō” or “mirage.” Further, shinkirō can be broken down into shin (“clam”), ki (“breath”), and rō (“tower”), referring to the shen’s towers of clam breath (Meyer).
Image of a Japanese woodblock print depicting a clam breathing a vapor. Another illustration depicts a Japanese city suspended in a mirage-vapor.
Note the pin-holes and damage close to the gutter (middle of the book where the right and left leaves meet). These are worm holes, created by paper-eating insects, like bookworms and silverfish. Fun fact: the Japanese term for silverfish is shimi (しみ). Shimi also can refer to someone unable to apply what they have read.

Strictly speaking, shinkirō are not a yōkai, but kaii, which are supernatural phenomena. In Japanese legend, oceanic mirages appear when gigantic clams — called shen–breathe out ki, or life energy. These illusions are called shinkirō, which is also the Japanese word for mirage, and usually take the form of magnificent, multi-storied cities with towering palaces and pagodas (Sekian et al. 165). Shen clams are said to exhale their ethereal cities on still nights, and their cities remain untouchable on the horizon, no matter how far mariners travel to reach them (Meyer). Interestingly, legends relate the shen clams and their shinkirō to sea dragons, and some legends even say that the illusory cities are an aspect of Ryūgū-jō (竜宮城, 龍宮城; “Dragon Palace Castle”), the oceanic palace of Ryūjin, the draconic sea god of Japanese mythology.

The legend of the shen and shinkirō most likely stems from optical phenomena known as Fata Morgana (Fata Morgana is the Italian translation of “Morgan the Fairy”, which refers to Morgana le Fay of Arthurian legend, who this mirage is named after). A Fata Morgana is a complex mirage of distant objects caused by light refraction due to differences in atmospheric temperature (Sekian et al. 165). These superior mirages, which appear on the horizon, often appear as floating and shifting structures.

Shinkirō are not the only myths likely inspired by the Fata Morgana– in the Western world, the myth of the Flying Dutchman, a phantom pirate ship doomed to sail the seas forever, is probably also caused by this phenomenon. (Does this make the Flying Dutchman and shinkirō cousins? Hmm.)

Image of a miniature book made from two halves of a clamshell, with one half painted with a vaporous mirage image. The other half houses a Japanese book, which is folded outward to reveal the text within, written in kanji.
Miniature book entitled “Mirage” (PL801.K8 M61 2013) by Ryūnosuke Akutagawa and illustrated by Minami Asano in 2013. Asano painted a shinkirō (mirage) inside one half of the clamshell, while the other houses Akutagawa’s short story “A Mirage,” which was published in 1927. The miniature book was inkjet-printed and bound in the Japanese binding style of nori-ire-bon, which was traditionally used to bind sacred Buddhist texts.

YŌKAI #5: NURIBOTOKE (塗仏)

  • NAME MEANING(S): “Coated Buddha” or “Lacquered Buddha”
  • HABITAT: Unkept houses and family shrines (仏壇; butsudan, meaning “Buddhist altar”)
  • DIET: None
  • DANGER LEVEL: Relatevely harmless (deceitful and a nuisance); Possibly High if another being in disguise
  • LILLY LIBRARY APPEARANCES: NC1764.5.J3 P374 2010, NC991.K22 G8
Image of a ghoulish humanoid spirit with pitch-black skin, dangling eyeballs, and a wide smile.
Woodblock relief print of a nuribotoke (塗仏; “coated Buddha”) from Kyōsai Kawanabe’s Gyōsai Manga: shohen (NC991.K22 G8), which was published by Makino Yoshibei in Tokyo in 1881. The last character in the kanji in the upper right corner is “fó” (佛), which refers to both the Buddha and Buddhism. Or this case, a zombified spirit taking the guise of a Buddhist priest (also called a bonze).

One of the creepier yōkai on our list, the nuribotoke (塗仏) is a cautionary tale of what may slip in when doors are not properly closed. In most Japanese Buddhist households in Japan, cabinet-like shrines known as butsudan are used to house venerated objects called gohonzon (御本尊), which can be spirit tablets (ihai), mandala scrolls, statues of a bodhisattva or the Buddha, and other holy objects. The butsudan is also used to honor a family’s ancestors, and is seen as the spiritual center of the home, enough so that during holidays, it is even offered treats like cake and sake (Meyer). The butsudan is left open during the day and always closed at night, as it is believed it functions as a doorway into the spirit world (Meyer). Thus, when the butsudan is not taken care or its doors are left open after sundown, a portal is left open between this world and the next, and beings like the nuribotoke may pay a family a much unwanted visit.

The kanji that make up the nuribotoke’s name literally translates as 塗 (nuri) meaning “coating” or “lacquering” combined with 仏 (botoke) meaning “Buddha.” This Coated Buddha is a sinister sight– appearing as zombified, pungent corpses with flabby and oily dark skin, largely bloated stomachs, and on occasion, a catfish-like tail that protrudes from the spine. The nuribotoke’s most distinctive feature is their eyes, which dangle out from their eye sockets (Meyer). While they are possibly the world’s worst surprise guest, luckily, they are not all that physically dangerous (I would still be very emotionally scarred). Once they creep out of the butsudan, they will flop around a household, not unlike a fish. They are also known to claim to be a messenger of the Buddha before uttering false prophecies in hopes of deceiving foolish mortals (Meyer). Never fear, however! The nuribotoke can be repelled by sprinkling salt on the floor, as they cannot cross it. They also must return from whence they came through the butsudan before the sun rises, or they will vanish. (Good riddance!)

Image of a frightening spirit with pitch-black skin, dangling eyeballs, and a fish-like tail.
An Edo-period illustration of the nuribotoke from Sawaki Suushi’s Hyakkai-Zukan (百怪図巻; “The Illustrated Volume of a Hundred Demons”) cited in Zilia Papp’s Traditional Monster Imagery in Manga, Anime and Japanese Cinema (NC1764.5.J3 P374 2010). Note the nuribotoke’s occasional catfish tail is visible, growing from its back. The catfish tail hints that the reanimated corpse might be controlled by another being or even another yōkai in disguise.

About the author: Jake H. Gentry is a 25-year-old gay author, artist, and graduate student. He received his Master of Library Science with a specialization in Rare Books and Manuscripts at Indiana University Bloomington, where he is now also pursuing his MA in Curatorship. He is a curatorial and teaching/outreach assistant at the Lilly Library. He lives in Bloomington, Indiana with his partner and his two cats, Poe and Jiji.

Works Cited and Consulted

Foster, Michael Dylan. Pandemonium and Parade: Japanese Monsters and the Culture of Yokai, University of California Press, 2008. ProQuest Ebook Central, http://ebookcentral.proquest.com/lib/iub-ebooks/detail.action?docID=837291. Created from iub-ebooks on 2025-07-08 15:31:11.

Davis, Frederick Hadland, and Evelyn Paul. “Myths & Legends of Japan.” Internet Archive, London: George G. Harrap, 1 Jan. 1970, p. 347. archive.org/details/mythslegendsofja00davi/page/346/mode/2up?q=baku. 

Meyer, Matthew. “Yokai.Com.” Yokai.Com | The Illustrated Database of Japanese Folklore, yokai.com/. Accessed 17 July 2025. 

Nakagawa, Masako. “Sankai ibutsu: An early seventeenth-century Japanese illustrated manuscript”. Sino-Japanese Studies, 1999. 11 (24–38): 33–34.

Toriyama, Sekien, Hiroko Yoda, and Matt Alt. Japandemonium Illustrated: The Yokai Encyclopedias of Toriyama Sekien. Mineola, New York: Dover Publications, Inc., 2016, https://books.google.com/books?id=Hj9-rgEACAAJ&pg=PT182#v=onepage&q&f=fals

“Baku: Monster That Eats Nightmares.” Baku: Monster That Eats Nightmares | LACMA Collections, collections.lacma.org/node/192199. Accessed 17 July 2025. 

Manyoshu. Full Text of “Manyoshu,” on Internet Archive, archive.org/stream/Manyoshu/Anonymous%201000%20Poems%20from%20the%20Manyoshu%20The%20Complete%20Nippon%20Gakujutsu%20Shinkokai%20Translation%20%20%20%201965_djvu.txt. Accessed 17 July 2025.

“Man’yōshū (Amasaki Book) Chapter 16.” Ma9sh0040.Html, pp. 77-78, web.archive.org/web/20160303201720/edb.kulib.kyoto-u.ac.jp/exhibit/ma9/image/ma9shf/ma9sh0040.html. Accessed 17 July 2025.

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