A cow found torn open at dawn needed an explanation. No wolf tracks. No dog had barked. In parts of western Japan, from at least the 1600s, that explanation had a name: Shii (𤯝). Old books describe it as a weasel-shaped beast. It killed cattle and horses at night, then vanished before anyone got a clear look at it.
What did Shii look like?
Most accounts agree on one point. Shii looked like itachi, the common Japanese weasel: slim, fast, low to the ground. A 1663 record from Hagi (in today's Yamaguchi) instead compares it to a badger or tanuki. After that, the stories split even further.
In Wakayama and Hiroshima, people also called it yama-arashi, the word for a porcupine. Cattle were said to fear it badly when its fur stood on end. So drovers shouted "shii, shii" to make a cow walk forward. The call meant "Shii is behind you."
A stone marker at Fukuchiyama Dam, near Nogata in Fukuoka, keeps a local version of the story alive. There the creature goes by another name, Shiiraku.
In Nagato, Yamaguchi, one village told it differently. If the fire games of Bon, the summer festival for the dead, were skipped, a one-eyed thing called Shii rose from the water. Then many cattle died.
A cattle-killer with a temper
The natural-history text Yamato Honzō, compiled by the scholar Kaibara Ekken in 1709, places Shii in Suo (today's eastern Yamaguchi) and Tsukushi (today's Fukuoka) provinces and calls it a menace to livestock. It adds one more detail: the creature was clever as well as fast, which is why so few farmers ever managed to trap or kill one.
A later book, the Saikai Zokudan of 1758, records a rougher version of the legend from the Yoshino mountains in Nara. There, it says, a person only had to touch the animal to come away hurt: cut across the face, hands, feet, even the throat. Whether this was the same beast recorded further west, or a second creature that had picked up the same name, the old sources never settle.
Living with a beast you cannot see coming
Villages that believed in Shii built rules around it. In Nagato, Yamaguchi, farmers kept a list of taboos. Do not work a cow on the fifth day of the fifth month. Do not let a woman carry the cow's gear. Do not lead in another village's cow before the first day of the eighth month. Break a rule, and Shii would come and eat the cattle. None of these rules fight Shii directly. They only try not to invite it.
Where it comes from
Shii reads as a name given to an old, ordinary problem: livestock dying in the night for no visible reason. A predator, a disease, or a simple accident could account for a single loss. A pattern of them, in the same stretch of country, asked for a story that explained the pattern, and the story arrived with teeth and fur.
Amano Sadakage, a scholar of the Edo period (1603–1868), complicated the picture. In his essay Shiojiri, he wrote that the creature called shii in Chinese sources was the same thing Japan already called kamaitachi. Kamaitachi is a cut that appears on the skin with no visible cause, blamed on invisible blades of wind. If he was right, the weasel that farmers in Suo and Tsukushi feared may have borrowed its name from a very different kind of monster, one made of wind rather than muscle. The two traditions stayed separate in practice. Kamaitachi cut without touching. Shii, in the Yamato Honzō, was a physical animal that preyed on livestock.
Shii today
Shii stayed a farmers' worry, tied to barns and night pastures, and never grew into a national figure. No temple mascot wears its face, and it has not turned up in a well-known anime or game. Its clearest trace left is that stone marker at Fukuchiyama Dam, still telling visitors the local Shiiraku story. Outside the corner of Japan it was recorded in, almost no one has heard of it at all.
