Tradition: Japanese Mythology
Alternative Names: Saru Kaachi, Saru-ga-Achi, 猿があち
Category: Monkey
The Myth
Saru-ga-Achi is a monstrous ape depicted in an account from Ōya Mountain in Shimotsuke Province, Japan. It lurks in a rocky cave near a waterfall, where it attacks horses by biting into their legs. Bones from its previous victims litter the ground around its lair. The name appears to derive from a regional expression meaning something like a strange or monstrous monkey, although another account interprets it as referring to a supernatural creature called an achi.
According to this later interpretation, monkeys grow into hihi as they age. These enormous ape-like monsters stand twice as tall as humans, have long lips and dishevelled hair, run at tremendous speed, and devour people. After several hundred more years, a hihi may die and subsequently return to life, becoming an achi. Such beings possess extraordinary supernatural powers, can communicate with Heaven, transform the forces of yin and yang, and summon clouds and rain.
Around 1199–1201, during the reign of Emperor Tsuchimikado, the warrior Inage Saburō Shigenari of Sagami Province reportedly encountered the Saru-ga-Achi while hunting on Ōya Mountain. By then, the creature’s formerly brown fur had turned yellowish white, and its back was bent. It appeared exhausted and close to death, as though waiting for its final moments. What eventually became of the ancient monster remains unknown.
Sources
“Saru-ga-achi.” 新版TYZ 妖怪図鑑 (New TYZ Yokai Encyclopedia). https://tyz-yokai.blog.jp/archives/1049058496.html