|Image Credit: tvojtatkooo|
There are different nine-tailed foxes with different stories. For this post, I'll focus on the Kumiho.
|Image credit: iGoMid|
It is unclear at which point in time Koreans began viewing the Kumiho as a purely evil creature, since many of the ancient texts mention benevolent Kumihos assisting humans. In fact, many of the older texts make more frequent mention of wicked humans tricking kind but naive Kumihos.
As the mythology of the Kumiho evolved, it was later believed that the creature had to consume human hearts in order to survive. Another version of the mythology, however, holds that with enough will, a Kumiho could become fully, permanently human and lose its evil character.