Tsuchigumo (土蜘蛛), literally "earth spider," is a Japanese historical term pejoratively referring to renegade clans, as well as the name of a spider yōkai (spirit) in folklore.
In mythology, the terms yatsukahagi (八握脛) and ōgumo (大蜘蛛, "giant spider") are variants.
In the Kojiki and Nihon Shoki chronicles, the homophone synonym 都知久母 is used, as well as in the fudoki of Mutsu, Echigo, Hitachi, Settsu, Bungo, Hizen, etc.
The Japanese name for the broad species of tarantulas ōtsuchigumo comes from the resemblance to tsuchigumo, although the myth does not make this connection.
No species of tarantula is native to Japan, so the similarity to the large spiders in folklore that like to hide underground is coincidental (the fact that no species of tarantula is native to Japan is in no way evidence of no etymological connection; the myth may well have an exogenous origin).
The various later myths mentioning a tiger body suggest Haplopelma hainanum, commonly known as the "earth tiger" in China for its hairy, striped body and aggressiveness, as the source of inspiration.
According to the scholar Motoori Norinaga, the term tsuchigumo was used in ancient Japan as a pejorative term for natives who did not pledge allegiance to the emperor.
There are debates about the historical or mythological origin of the word. One view is based on ancient historical documents reporting that rebels waging war against the emperor were described as oni ("demons") at court, reflecting both contempt and a willingness to associate such enemies directly with demons.
Tsuchigumo may have been an older, obscure myth taken up to refer to lesser threats to the court, thus gaining popularity. A second view derives the term tsuchigumo from tsuchigomori (土隠), literally "those who hide in the earth."
This term characterized a widespread practice among rural clans, the use of natural caves and the creation of hollow, fortified mounds for military and residential purposes.
This origin suggests that calling the renegade clans tsuchigumo was originally a pun that gradually took on the meaning of intelligent or even anthropomorphic spiders, first allegorically and then as a myth in its own right.
In ancient historical chronicles, tsuchigumo is used for individuals - bandits, rebels, rebellious clan leaders - as well as for entire clans, although the meaning sometimes remains ambiguous.
In any case, it refers to people or clans who repeatedly and more or less anonymously defied the emperor's authority, usually by guerrilla warfare or concealment of wealth.
The clans of the Yamato Katsuragi-san mountains were particularly well known among the tsuchigumo.
The Katsuragi-hitokotonushi-jinja stands on a mound possibly created by tsuchigumo; legend has it that emperor Jinmu had the head, body and feet of captured tsuchigumo buried there separately so that they would not live again.
In the region of Yamato (nowadays essentially the prefecture of Nara), the folklore lends to the tsuchigumo a physical characteristic which is not found elsewhere, that of having a tail.
This feature is found in the Nihon Shoki where the founder of the Yoshino no Futo (吉野首) has a "glorious tail" and the founder of the Yoshino no Kuzu (国樔) "has tails that can move large boulders (磐石, iwa)"; the natives of the region are thus described as non-human.
Even in the Kojiki, the people of the area of present-day Sakurai are "tsuchigumo who have a full-grown tail".
The year 72 of the Hizen no Kuni fudoki reports that Emperor Keikō on his way to Shiki (志式島) Island (Hirado) discovered two islands with his expedition.
Seeing smoke rising from them, the emperor decided to explore them and discovered that the tsuchigumo Oomimi (大耳) lived on the smaller island, while Taremimi (垂耳) lived on the larger one.
Captured and on the verge of death, both prostrated themselves before the emperor, begging forgiveness and declaring that they would now "pay tribute" to him.
In the Bungo no Kuni fudoki, many tsuchigumo appear, such as the Itsuma-hime (五馬姫) of Itsuma Mountain (五馬山); the Uchisaru (打猴), Unasaru (頸猴), Yata (八田 ), Kunimaro (國摩侶) and Amashino (網磯野) of the Negi Plain (禰宜野), the Shinokaomi (小竹鹿臣) of Shinokaosa (小竹鹿奥); and finally the Ao (青) and Shiro (白) of Nezumi Cave (鼠の磐窟).
In addition, there is the story of the Tsuchigumo Yasome (土蜘蛛八十女), rebels finally defeated by the imperial court. The term "yaso" (八十), literally eighty, figuratively means "many," and "me" means "woman"; it is possible that several women of clan chiefs opposed to the court met a heroic end by dying among the men.
But it is also reported that these Tsuchigumo Yasome, women chiefs of local clans, disassociated themselves from the renegades and were thus spared by the imperial court.
According to the Nihon Shoki, Emperor Keikō arrived in Hayami (Ookita) when he was twelve years old (in the year 82 of the chronicles), and he learned from the local queen, Hayatsuhime (速津媛), of the existence of a vast cave in the mountains named Nezumi where two tsuchigumo, Shiro and Ao, lived.
Then in Negino (禰疑野) (Naoiri), he was told of three other tsuchigumo named Uchizaru (打猿), Yata (八田) and Kunimaro (国摩侶, 国麻呂). These five men had many allies, and would have refused to follow the emperor's orders.
In time, the tsuchigumo also became a yōkai. In folklore, they were described with oni heads, spider arms and legs, wearing giant clothes, and living in the mountains where they captured travelers in their webs to devour them.
In the Tsuchigumo sōshi (土蜘蛛草紙) from the 14th century, tsuchigumo appear in the capital as monsters.
The story goes that the commander Minamoto no Yorimitsu (mid-Heian period), known for slaying Shuten-dōji, encountered a flying skull with his servant Watanabe no Tsuna on a mountain north of Kyoto.
Yorimitsu followed him to an old estate where various yōkai tormented them. Then at dawn, a beautiful woman appeared to trick them, but Yorimitsu sliced her with his katana.
Continuing their journey, they came to a cave in a fold of the mountain where there was a giant spider, the true form of all the previous monsters. Yorimitsu cut off the head of the spider after a long battle, and the heads of 1990 dead people came out of the monster's stomach.
In addition, a multitude of small spiders escaped from its sides and twenty skulls were found.
There are several hypotheses as to the origin of this story. In the Heike monogatari, a strange and very tall monk appeared to Yorimitsu, who was bedridden with malaria, to capture him.
Despite his illness, Yorimitsu wounded him with his famous sword, Hizamaru (膝丸), forcing him to flee.
The next day, he led his four guard kings on the monk's bloody trail to a mound behind the Kitano-jinja, where they discovered a giant 1.2-meter-wide spider (4 shaku).
Yorimitsu and his people captured it, pierced it with an iron spike, and put it on display by a river. Immediately his illness left him, so he named his sword Kumo-kiri (蜘蛛切り), "spider slicer ".
The true identity of the tsuchigumo is described as the onryō ("avenging spirit") of a former local clan chief defeated by the emperor Jinmu. This tale is also reported in the noh play Tsuchigumo.
In another story, Yorimitsu's father, Minamoto no Mitsunaka, conspired with an oni and a local tsuchigumo clan against the Fujiwara clan.
However, it is said that during the Anna no Hen (安和の変, "Anna incident") in 969, he betrayed the tsuchigumo clan to protect himself, so that his son Yorimitsu and his guardian kings were reportedly cursed by tsuchigumo yōkai and oni.
At the Jōbonrendai-ji in Kyoto is a stele, Ason-no-tsuka (源頼光朝臣塚?), identifying an ancient mound in a cemetery, which legend says was a tsuchigumo mound; a woodcutter who felled a tree near the mound mysteriously fell ill and died.
Another mound in Kyoto's Ichijō-dōri was according to myth built by a tsuchigumo, and lanterns found during an excavation were associated with these spiders; as it was said that these lanterns could bring fortune as well as curse to the tsuchigumo, they were entrusted to the Tōkō-Kannon-ji of Kyoto.
There is a similar yōkai named umigumo (海蜘蛛) living on the Kyūshū coast, who can throw threads from their mouths and attack people.