Tradition: Chinese Mythology
Alternative Names: 陰鼠, Hidden Rodent, Hidden Mouse
Category: Rat
The Myth
Yin Shu, meaning “Hidden Rodent” or “Hidden Mouse,” is a legendary subterranean creature described in Chinese writings, including the Li Ji (Book of Rites) in some accounts. It dwells in dark caves and underground passages, rarely emerging into the open. Similar beliefs were recorded in Siberia, where mammoth fossils were interpreted as the remains of enormous mole-like beasts that tunneled beneath the earth, tearing up riverbanks as they moved. These creatures were believed to die when exposed to daylight.
Descriptions of the Yin Shu vary between sources. It is generally portrayed as a gigantic, dark, mouse-like animal, with accounts from Manchurian manuscripts claiming it can grow from the size of a buffalo to that of an elephant. It has short legs, a short neck, small eyes, and either no tail or only a stub. Despite its immense strength, it is said to be slow-moving and unintelligent, digging extensive underground chambers in places where the fu-kia plant grows. Floods that inundate plains were sometimes believed to drive these hidden beasts into view, where sunlight would kill them.
The legend became associated with the discovery of prehistoric remains. Mammoth bones were reportedly sold in Chinese drugstores under the name Yin Shu, reflecting the belief that such enormous fossils belonged to giant rodents living beneath the earth. The creature therefore represents a folkloric explanation for the mysterious bones of extinct animals, combining subterranean monster traditions with early interpretations of paleontological discoveries.
Sources
“Yin Shu.” A Book of Creatures. https://abookofcreatures.com/?s=Yin+Shu