Yamakachi is a name used on English-language cryptid websites for a giant snake said to live on Mount Tsurugi (Tsurugisan) in Tokushima Prefecture, on the island of Shikoku, Japan. In Japanese sources, the creature is simply called the giant serpent (daija) or orochi of Mount Tsurugi. It became famous after a series of sightings in May 1973, when forest workers reported a black snake with a white belly more than 10 meters long, prompting a search by over a hundred people. Nothing was found. Earlier versions of this entry described the Yamakachi as a furry, man-like mountain guardian; we have found no source for that description, and it appears to have been invented.[1][2]
| Location | Mount Tsurugi (Tsurugisan), Tokushima Prefecture, Shikoku, Japan |
|---|---|
| Japanese names | Tsurugisan no daija (giant serpent of Mount Tsurugi), orochi |
| Description | A giant black snake with a white belly; head said to be the size of a propane cylinder |
| Claimed length | 10 meters or more |
| Key sightings | May 1973, including 26 May 1973 |
| Search | A party of over 100 people; no snake found |
| Likely explanations | Exaggerated sightings of known animals, an escaped exotic snake, or a large eel |
Mount Tsurugi
Mount Tsurugi, at about 1,955 meters, is one of the highest mountains on Shikoku and a sacred mountain in Japanese mountain religion, with shrines and pilgrimage routes. It also has an unusual modern legend: that the treasure of King Solomon is hidden somewhere on the mountain. In the 1970s, a rumor circulated that the giant snake was guarding that treasure.[2]
The 1973 sightings
According to an account published in 2014 by the Tokushima-born occult writer Tetsutaro Yamaguchi in the newspaper Tokyo Sports, three men cutting grass on the mountain in May 1973 were confronted by a huge snake that raised its head from the grass; its open mouth alone was said to be at least 2.5 meters across. On 26 May, the same men, accompanied by a local town councillor, saw it again. This time they described a head about the size of a propane gas cylinder and a body at least 10 meters long.[1][2]
Further reports followed, and people said they found giant shed skins and the tracks of a large animal moving through the undergrowth. A search party of more than a hundred people was organized, but no snake was found, and the creature’s fate is unknown. The English-language Cryptid Wiki describes it as a black snake with a white stomach and says villagers took to carrying weapons.[1][2]
Yamaguchi also recorded an older local story from the Taishō era (1912–1926) of a hunter who met a great snake on the mountain, fell ill with a fever and died three days later. He heard it from an aunt, who had it from someone present at the death.[2]
Could a giant snake live in Japan?
Japan has no native snake anywhere near 10 meters long. The largest snake of the main islands, the Japanese rat snake (aodaishō), reaches about 2 meters. In a 2022 Tokyo Sports conversation, the writer Tatsuro Jikiyoshi, credited with coining the Japanese term “UMA” for cryptids, made exactly that point. Yamaguchi himself has suggested two possibilities:[3]
- An escaped exotic snake. Exotic animals were displayed in circuses and sideshows in Japan before and after the war, and a large python or anaconda might have escaped. Such a snake would struggle to survive the winters of a high mountain, which might explain why none was ever found.[2]
- A giant eel. Japan’s giant mottled eel (ōunagi) can grow very large and sometimes crosses land in wet weather. Seen briefly in long grass, a big eel could easily be mistaken for a snake and its size exaggerated.[3]
Other factors probably played a part: the difficulty of judging size in thick vegetation, the excitement of a story already in circulation, and the rumors about treasure and UFOs that grew around the sightings. Yamaguchi notes that some accounts claimed the snake glowed, which fueled a theory that it was a radioactive creature from a UFO.[2]
Giant snakes in Japanese tradition
Giant serpents have a long history in Japanese myth and folklore, most famously the eight-headed Yamata no Orochi slain by the storm god Susanoo in the ancient chronicles. Snake spirits are associated with mountains, water and the guarding of sacred places. The Mount Tsurugi snake sits between these traditions and modern “UMA” culture, which also produced Japan’s famous stubby snake cryptid, the tsuchinoko, and the ape-like Hibagon reported near Mount Hiba in Hiroshima Prefecture from 1970.[4]
About the name
We have not found the name “Yamakachi” in Japanese sources, which refer to the Mount Tsurugi creature as a daija or orochi. The name appears to be used mainly by English-language websites. Readers should be cautious about details, such as a humanoid form, a protective role or 1950s mountaineering encounters, that have been attached to the name online without a traceable source.
Our assessment
The “Yamakachi” is best understood as the giant snake of Mount Tsurugi, a short-lived 1970s monster story from a mountain already rich in legend. The sightings were reported by named local witnesses and drew a large search, but no snake was found, and no snake of that size could survive in the wild in Japan. An escaped exotic snake, a large eel or an exaggerated sighting of a known snake are far more likely than an undiscovered species.
References
- “Yamakachi,” Cryptid Wiki (Fandom).
- Tetsutaro Yamaguchi, “剣山のオロチ” (The Orochi of Mount Tsurugi), Tokyo Sports (2014, in Japanese).
- Tetsutaro Yamaguchi and Tatsuro Jikiyoshi, UMA dialogue, Tokyo Sports (30 December 2022, in Japanese).
- “Hibagon,” Wikipedia.
Correction note (October 2026): This entry was rewritten from documented sources. Earlier versions described the Yamakachi as a furry, humanoid mountain guardian with a 1950s mountaineers’ sighting; the only sources we found describe a giant snake reported on Mount Tsurugi in 1973. The illustration above is an artistic impression and may not match the reports.