Nurarihyon (滑瓢 or ぬらりひょん) is a Japanese yōkai.

Generally, like the hyōtannamazu, they are considered a monster that cannot be caught. One can find that it often appears in the yōkai emaki of the Edo Period, but any further details about it are unknown. In folktale legends, they are a member of the Hyakki Yagyō (in the Akita Prefecture), and there is a type of umibōzu in the Okayama prefecture that can be found under that name, but it is not clear whether they came before or after the "nurarihyon" in the pictures.

It has been thought that they are a "supreme commander of yōkai," but this has been determined to be simply a misinformed or common saying, as detailed in a later section.

In the Edo Period Japanese dictionary, the Rigen Shūran, there is only the explanation "monster painting by Kohōgen Motonobu." According to the Edo Period writing Kiyū Shōran (嬉遊笑覧), it can be seen that one of the yōkai that it notes is depicted in the Bakemono E (化物絵) drawn by Kōhōgen Motonobu is one by the name of "nurarihyon," and it is also depicted in the Hyakkai Zukan (1737, Sawaki Suushi) and the Hyakki Yagyō Emaki (1832, Oda Gōchō, in the Matsui Library), among many other emakimono. It is a bald old man with an elongated head, and depicted wearing either a kimono or a kasaya. Without any explanatory text, it is unclear what kind of yōkai they were intending to depict.

The Kōshoku Haidokusan (好色敗毒散), a ukiyo-zōshi published in the Edo Period gives the example, "its form was nurarihyon, like a catfish without eyes or mouth, the very spirit of lies," so it is known that it is word used with a meaning similar to noppera-bō but as an adjective.

The Gazu Hyakki Yagyō by Toriyama Sekien depicts a nurarihyon hanging down from a kago. Like the emakimono, this one has no explanatory text, so not many details are known, but the act of disembarking from a vehicle was called "nurarin," so it is thought that nurarihyon was a name given to a depiction of this. Furthermore, it is also theorized that this depicts the libertines who go to the red light district. Natsuhiko Kyōgoku and Katsumi Tada posit that "nurari" is an onomatopoeic word meaning the state of slipperiness, and "hyon" similarly means a strange or unexpected circumstances, which is why "nurarihyon" was the name given to a yōkai that was slippery (nurarikurari) because it cannot be caught. In the Gazu Hyakkai Yagyō, its name is written as "nūrihyon" but considering all the literature and emakimono before it, it is generally thought that this is simply a mistake.

From its appearance, it is also theorized that this yōkai was born because an old person was mistaken for a yōkai.

Okayama Prefecture