Nukekubi

The rokurokubi (ろくろ首, 轆轤首) is a type of Japanese yōkai (apparition). They look almost completely like humans, with one major difference. There are two types of Rokurokubi: one whose necks stretch, and one whose heads come off and fly around freely (nukekubi). The Rokurokubi appear in classical kaidan (spirit tales) and in yōkai works. It has been suggested, however, that the idea of rokurokubi may have been created purely for entertainment purposes rather than originating from any folk beliefs or legends.

The word rokurokubi may have derived from the word rokuro which refers to a potter's wheel a water well's pulley (since it elongates). or an umbrella handle (which also elongates).

The nukekubi are rokurokubi whose heads come off and float about. These were the first rokurokubi, whereas the other kind came aftewards. Nukekubi sometimes perform bad deeds such as attacking at night and drinking their victims' blood. It's theorized that the nukekubi has a weakness when it is sleeping and the head is floating around: if the body moves, then the head cannot be re-united to the body. Classical literature about rokurokubi describe tales of people witnessing and encountering floating heads at night time.

Sometimes, the action of the head separating from the body is seen as the soul wandering away from the body i. e. somnambulism. For example, in the Sorori Monogatari (曾呂利物語, 1663 CE), in the chapter, A Woman's Wild Thoughts Wandering Around (女の妄念迷ひ歩く事, Onna no Mōnen Mayoiaruku Koto) the head separating from the body interpreted to be the woman's soul wandering while asleep. In the same book, a man saw a nukekubi that changed into a chick and a woman's head, so he took his sword and chased the head. The head fled into a home, and people said that they heard a voice from inside say, "I had a scary dream. I was chased by a man with a sword. I ran away all the way back home, and then I woke up." (refer to picture).

A similar story appears in Shokoku Hyaku Monogatari (諸国百物語, 1677 CE), which drew a lot of inspiration from the Sorori Monogatari. In About Rokurokubi in the Province of Echizen (ゑちぜんの国府中ろくろ首の事, Echizen no Kofuchuu Rokurokubi no Koto), there's the story of a man who chases a nukekubi (who was a woman's soul detached from her body) all the way home. It's said that the woman had been shamed by a crime she has committed, so as a result, she left her husband, shaved her hair, and committed suicide.

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Wikipedia