Kyūbi-no-kitsune (九尾の狐; the nine-tailed fox)

Region/Culture: East Asia (Japan)
Mythos: Japanese Mythology
Primary Type/Nature: Shapeshifters
Mythical Attributes: A fox that has lived roughly a thousand years and grown nine tails, gaining near-divine power, flawless transformation into human shape, foxfire, and illusions large enough to swallow a city.
Role in Mythos: It is the highest and most dangerous rank of the kitsune, a millennium-old fox spirit powerful enough to deceive emperors and pull down whole courts.
Relation to Humans: Mortals are the creatures it deceives and feeds upon, seduced in human guise while their vitality is quietly drawn away. Yet the same stories arm people against it, through dogs that are never fooled, diviners who can name it, and the theft of the star ball that holds its strength.

Count the tails and you count the centuries. A young fox has one, russet and unremarkable, and it hunts mice along the paddy dikes like any other animal. A fox that lives long enough begins to change. At a hundred years it grows a second tail, and it keeps growing them, one for each century it survives, its coat lightening as it ages past anything a fox should reach. By the time nine tails fan behind it, the creature has watched a thousand harvests come and go, and its fur has turned white or the pale gold of temple lacquer. Whatever it is by then, it is no longer an animal.

This is the kyūbi-no-kitsune, the nine-tailed fox, the oldest and most dangerous form a Japanese fox spirit can take. The tails are a ledger of age and of power, and the ninth is the last rung. A fox that reaches it becomes a tenko, a celestial or heavenly fox, said to leave the earth for the sky and to see and hear everything that happens beneath it. The old phrase gives it sight across a thousand li. Near the top of the ladder the line between fox and god thins to almost nothing, and the stories treat the creature as something close to divine, and close to unstoppable.

What it does with that power is wear a human face. Any kitsune of enough years can shapeshift, but the nine-tailed fox does it without a flaw, and it favours one shape above the rest: a beautiful woman. In the lamplit halls of a palace such a woman can answer any question put to her, on poetry or scripture or the turning of the stars, and when a gust snuffs the lamps and a soft light is seen to come off her own body, the court reads it as proof of her grace rather than what it is. She can throw foxfire too, the pale flame called kitsune-bi that flickers from her mouth or the tips of her tails, and she can raise illusions wide enough to hide a household or a whole city, so that men see safety where there is a trap. Somewhere on her, or hidden away, she keeps a small white orb, the hoshi no tama, the star ball, which holds her power the way a jar holds water. Take the star ball and she will do almost anything to have it back, because without it the great celestial creature is only a frightened animal that weakens and dies.

The fox did not begin in Japan. The nine-tailed fox is old across East Asia, first surfacing in Chinese texts as a strange beast of the mountains, and it travelled east the way ideas did, through the Korean peninsula, where it became the liver-eating kumiho, and on into the islands. The Japanese fox kept the Chinese lineage of ruin. In the fuller tellings, one fox spirit stands behind the concubines who toppled the early Chinese dynasties, so that by the time it reaches the Japanese court it already carries the fall of empires on its record.

That court is where its most famous story turns. In the twelfth century a woman named Tamamo-no-Mae came to the palace of the retired emperor Toba, and no one there could match her. The emperor doted on her. Then he fell ill, a wasting sickness that no physician could name, and as he weakened a court diviner named Abe no Yasuchika was called to read the cause. The reading was the fox. Tamamo-no-Mae was a nine-tailed fox, he said, and she was drawing the emperor’s life out of him from the inside. Cornered by the diviner’s rites, she could not hold the woman’s shape any longer. She dropped it and ran east.

She fled to the Nasu moor in Shimotsuke, and there she went back to open killing, taking livestock and travellers until the court sent two warriors, Kazusa-no-suke Hirotsune and Miura-no-suke Yoshiaki, to finish her. They ringed the plain and drove her, but she was hard to bring down. The night before the kill she came to Miura-no-suke in a dream, wearing again the lovely face of Tamamo-no-Mae, and she told him he would kill her in the morning and begged him not to. He refused. At first light the hunters found the fox out on the moor, and Miura-no-suke put an arrow through it.

That was not the end of her. Where the fox died, its body hardened into a boulder, the Sessho-seki, the killing stone, and the stone went on breathing out a poison so foul that birds dropped dead from the air above it and no one could go near. It sat steaming among the sulphur springs of Nasu for centuries, a killing thing that had only changed its shape one more time. In 2022 the stone was found split cleanly in two, and a good part of Japan noticed the date.

Her powers all run back to a single source, which is time. Long life grows the tails, the tails carry the shape-changing and the foxfire and the illusions, and the star ball gathers the whole of it into something small enough to hide in her mouth. Her weaknesses are the seams in that same disguise. Dogs are never fooled and will not stop barking. Water and mirrors and drink can show the fox beneath the woman. The rites of a diviner or a Buddhist monk can strip the human shape away, and whoever holds the star ball holds the fox. She can wear the most powerful face in the empire and still be undone by a farm dog that knows better.

Frequently Asked Questions

What is a Kyūbi-no-kitsune?

A Kyūbi-no-kitsune is the nine-tailed fox of Japanese folklore, the oldest and most powerful form of a kitsune, or fox spirit. It is a fox that has lived roughly a thousand years and grown nine tails, gaining near-divine power, flawless shapeshifting into human form, and the ability to conjure fire and illusions. In most stories it uses that power to deceive and prey on people.

How does a fox become a nine-tailed fox?

A fox becomes a nine-tailed fox through extreme age, growing one additional tail for roughly every hundred years it lives until it reaches nine tails at about a thousand years old. When it gains the ninth tail its fur turns white or gold and it becomes a tenko, a celestial or “sky” fox with the greatest power a fox spirit can hold. The number of tails is a direct measure of a kitsune’s age and strength.

What powers does the nine-tailed fox have?

The nine-tailed fox can transform perfectly into human shape, most often a beautiful woman, and it can produce foxfire (kitsune-bi) and cast illusions large enough to fool an entire household or city. As a celestial fox it is said to see and hear everything happening in the world. Much of its power is bound up in a small orb called the hoshi no tama, or star ball, without which it grows weak.

Who was Tamamo-no-Mae?

Tamamo-no-Mae was the most famous nine-tailed fox in Japanese legend, a beautiful courtesan who served the retired emperor Toba in the twelfth century and secretly drained his life force. The court diviner Abe no Yasuchika exposed her as a fox, and she fled to the Nasu moor, where warriors hunted and killed her. Her body then became the Sessho-seki, the poison-breathing Killing Stone.

How do you defeat or detect a nine-tailed fox?

Dogs can always sense a nine-tailed fox and will bark at or attack it despite its disguise, and its true fox form can be revealed in reflections, in water, or when it is careless. The rites of a diviner or Buddhist monk can strip away its human shape, and taking its star ball leaves it weak enough to kill. In the Tamamo-no-Mae legend the fox was finally brought down on the Nasu plain with an arrow.