Yaoguai

Also Known As: 妖怪; from yao 妖, a portent or uncanny thing, and guai 怪, the strange; used as a compound by Gan Bao in the fourth-century Soushen ji
Region/Culture: East Asia
Mythos: Chinese Mythology
Primary Type/Nature: Shapeshifters
Mythical Attributes: A yaoguai is a thing whose essence has come loose from its proper form, most often an animal grown so old that it can borrow a human body, though it can never change its true shape in a mirror.
Role in Mythos: Yaoguai are the broad Chinese class of anomalies and uncanny beings, read in the oldest texts as portents of disorder and in later fiction as the monsters that crowd the road to the west.
Relation to Humans: They test, deceive and prey on people, usually by walking up to them in a borrowed human shape. The early writers were equally interested in the other direction, holding that the anomaly rises out of human failings, and that a traveller with the right mirror could make it drop its disguise.

Two Daoists sat meditating in a stone chamber on Yuntai Mountain in Shu when a stranger walked in. He wore a single robe of yellow silk and a headcloth of coarse kudzu cloth, and he greeted them kindly: hard work, living hidden away like this. The two men turned and looked into their mirror. In the polished bronze stood an old deer. They told it so to its face, and before the words were out of their mouths the visitor was a deer again, clattering out of the cave and away down the mountain.

Ge Hong set that story down around the year 317, in the chapter of his Baopuzi on climbing mountains and crossing rivers, and he gave the rule behind it in plain terms. The essences of all old things can borrow a human shape to dazzle people’s eyes and test them. What they cannot do is change their true form in a mirror. So the Daoists of old who went into the mountains hung a bright mirror nine inches or more across on their backs, and the old goblins would not come near.

That is the yaoguai at work in its most ordinary mode. It does not burst out of the dark. It walks up in good clothes and makes conversation.

The word is older than any of the creatures. Guai is simply the strange, and it sits in one of the most quoted lines in the Analects: the Master did not speak of anomalies, feats of strength, disorder or spirits. Yao is the portent. The Zuo Tradition records that in 680 BCE two snakes fought at the south gate of the state of Zheng, one from inside the wall and one from outside, and the inner snake died. When Duke Zhuang of Lu asked whether such a thing meant anything, the official Shen Xu gave an answer that set the tone for centuries. Portents arise from people. If people give them no opening, they do not appear of themselves. When people abandon the constant, the portents flourish.

Gan Bao, the court historian who compiled the Soushen ji in the middle of the fourth century, fused the two words and defined them. A yaoguai, he wrote, is essence and vital breath that has attached itself to a thing. When the breath is disordered within, the thing is transformed without. He filled a whole scroll with the evidence: a mountain that vanished in the time of Jie of Xia, a great turtle that grew hair and hares that grew horns before armies marched, a horse that turned into a fox in the reign of King Xuan of Zhou. In that oldest sense a yaoguai is not a species. It is the world misbehaving where someone can see it.

The creatures came from the same logic run over time. Age is the engine. In another scroll Gan Bao lists what the years do: a thousand-year pheasant enters the sea and becomes a giant clam, a hundred-year sparrow becomes a small one, a thousand-year turtle can talk with people, a thousand-year fox rises up as a beautiful woman, a thousand-year snake cut in two joins itself back together, a hundred-year rat can tell fortunes. It is, he says, the fullness of their count. Ge Hong kept a similar ledger with different numbers. Foxes, wildcats, dholes and wolves live eight hundred years, and at five hundred they become skilled at taking human form. A bear of five hundred can transform. Tigers, deer and hares live a thousand years, though what their five-hundredth birthday brings them is only a white coat. A macaque of eight hundred becomes an ape, and an ape of five hundred becomes the jue.

Nothing in these lists was born a monster. Every one of them started as an ordinary animal and simply refused to stop.

Not every anomaly is a patient animal, and Gan Bao declines to tidy the category. He records that in the Qin period the south held a people whose heads could fly, and that a general of Wu named Zhu Huan once bought a maidservant whose head left her body every night after she lay down to sleep.

The book that fixed the word in the popular imagination is the sixteenth-century novel Journey to the West, in which a Tang monk walks toward India through what amounts to a corridor of yaoguai. The plot runs on a rumour. Anyone who eats a single piece of the monk’s flesh, the demons say, will live forever. In the twenty-seventh chapter a corpse demon on White Tiger Ridge wants that piece badly enough to try three times. First she is a lovely girl carrying a blue clay jar in her left hand and a green porcelain bottle in her right, offering the pilgrims a meal. Sun Wukong strikes her down, the demon slips away leaving a body behind, and the food in the jars turns out to be long-tailed maggots, frogs and toads. Next she is a woman of eighty, hobbling on a crutch and weeping for her lost daughter. Then an old man with a dragon-headed staff and a light crane-feather cloak, chanting scripture as he walks up the road.

The third blow lands for good, and on the path lies a heap of powdery bones with a line of writing down the spine: Lady White Bone. It proves nothing to the monk. Zhu Bajie persuades him that Wukong conjured the skeleton to cover three murders, and Tang Sanzang writes out a formal letter dismissing his disciple. Seeing through a yaoguai turns out to be the easy part.

Their powers are the powers of long practice: the borrowed face and the borrowed voice, the illusion laid over a meal or a room, the patience that lets a fox outlive a dynasty. A yaoguai is strongest exactly where it is most convincing, which is at arm’s length, in daylight, being polite.

Their weaknesses come from the same source. A borrowed shape is still borrowed, and the mirror shows the deer under the silk. Their power is counted in centuries, so a young one is little more than an animal with ambitions. And if Shen Xu was right, the surest defence was never a mirror at all. Where people keep to the constant, the strange has no opening to come through.

Frequently Asked Questions

What is a yaoguai in Chinese mythology?

A yaoguai is a strange or uncanny being in Chinese tradition, most often an animal or thing that has gained supernatural power, usually through great age. The fourth-century writer Gan Bao defined a yaoguai as vital essence that has attached itself to a thing, so that disorder inside shows as transformation outside. The best-known ability of a yaoguai is taking on a convincing human shape.

How does an animal become a yaoguai?

By living long enough. Ge Hong’s Baopuzi says foxes, wildcats, dholes and wolves live eight hundred years and become skilled at taking human form at five hundred. Gan Bao’s Soushen ji says a thousand-year-old fox rises up as a beautiful woman and a thousand-year-old turtle can talk with people.

How can you tell if someone is a yaoguai?

Look at them in a mirror. Ge Hong wrote that old creatures can borrow a human shape but cannot change their true form in a mirror, so Daoists entering the mountains hung a bright mirror nine inches or more across on their backs. In his story of two Daoists on Yuntai Mountain, a friendly visitor in a yellow silk robe showed up in the mirror as an old deer.

Who is the White Bone Demon in Journey to the West?

The White Bone Demon is a corpse demon in chapter 27 of Journey to the West who wants to eat Tang Sanzang, because a piece of his flesh is said to grant eternal life. She disguises herself as a young girl, an old woman of eighty and an old man, and Sun Wukong strikes down each disguise. Her true form is a pile of bones inscribed “Lady White Bone” on the spine, but the monk believes Zhu Bajie’s claim that Wukong faked it and dismisses him.

Where does the word yaoguai come from?

It joins yao, a portent or uncanny thing, and guai, the strange. The Zuo Tradition has the official Shen Xu say that portents arise from people and flourish when people abandon the constant, and the Analects records that Confucius would not speak of anomalies. Gan Bao used the compound yaoguai in the fourth-century Soushen ji.