The fox spirit (狐狸精) or nine-tailed fox (九尾狐), having been originated from Chinese mythology, is a common motif in the mythology of East Asian countries.
In East Asian folklore, foxes are depicted as a familiar spirit possessed of magic powers. These foxes are depicted as mischievous, usually tricking other people, with the ability to disguise as an attractive woman:
"The fox spirit is an especially prolific shapeshifter, known variously as the húli jīng (fox spirit) in China, the kitsune (fox) in Japan, and the kumiho (nine-tailed fox) in Korea. Although the specifics of the tales vary, these fox spirits can usually shapeshift, often taking the form of beautiful young women who attempt to seduce men, whether for mere mischief or to consume their bodies or spirits."
Nine-tailed foxes appear in Chinese folklore, literature, and mythology, in which, depending on the tale can be a good or a bad omen. The motif of nine-tailed foxes from Chinese culture were eventually transmitted and introduced to Korean and Japanese culture.
During the Han dynasty, the development of ideas about interspecies transformation had taken place in Chinese culture. The idea that non-human creatures with advancing age could assume human form is presented in works such as the Lunheng by Wang Chong (27-91). As these traditions developed, the fox's capacity for transformation was shaped.
The nine-tailed fox occurs in the Shanhaijing (Classic of Mountains and Seas), compiled from the Warring States period to the Western Han period (circa 4th to circa 1st century BC). The work states:
"The Land of Green-Hills lies north of Tianwu. The foxes there have four legs and nine tails. According to another version, it is located north of Sunrise Valley."
In chapter 14 of the Shanhaijing, Guo Pu had commented that the nine-tailed fox was an auspicious omen that appeared during times of peace. However, in chapter 1, another aspect of the nine-tailed fox is described: