Fox spirits in Chinese mythology are spirits of a fox type that are akin to European faeries and demons. They can be either good spirits or bad spirits.
In Chinese mythologies, it is believed that all things are capable of acquiring human forms, magical powers and immortality provided that they received certain energy, such as human breaths or essence from the moon and the sun.
The fox spirits that people encounter in tales and legends tend to be females and appear as young, beautiful women. One of the most infamous fox spirits in Chinese mythology was Daji, who is portrayed in the Ming novel Fengshen Yanyi a beautiful daughter of a general; she was married forcibly to the cruel tyrant Zhou Xin. A nine-tailed fox spirit who served Nvwa entered into the possessed her body, expelling the “true” Daji’s soul. “Daji” and her new husband schemed cruelly and invented many devices of torture, such as forcing righteous officials to hug red-hot metal pillars. Due to such cruelties, many people, including Zhou Xin’s own former generals, revolted and fought against Zhou Xin’s dynasty, Shang. Finally, King Wu of Zhou, one of the vassals of Shang, founded a new dynasty named after his country. The fox spirit in Daji’s body was late driven out by Jiang Ziya, the first Prime Minister of the Zhou Dynasty.
Typically fox spirits were seen as dangerous, but some of the stories in Pu Songling’s Liaozhai Zhiyi are love stories between a fox appearing as a beautiful girl and a young human male.
In modern Mandarin slang and Cantonese slang, the term “fox spirit” is a derogatory expression describing a woman who seduces a man.