Nine-tailed foxes are commonplace in folktales originating from Korea, China, and Japan. According to these legends, a fox that lives for a thousand years can turn into a fox spirit and shape-shift freely. Its most preferred form to take, though, would be that of a beautiful young girl who seduces men and makes a meal out of these unfortunate souls.
The Korean fairy-tale “The Fox Sister” features a couple with two sons who really wanted a daughter. Praying fervently for a daughter even if she were a fox, the family were indeed blessed with one. However, the happy and idyllic story soon took a turn for the gory when the family started to probe why their livestock was mysteriously dying off.
Investigations by the two sons culminated in accusations that their sister was the one responsible — accusations that their parents firmly rejected. Both sons were shown the door, and when they later returned, they found that the only one left in their family home was their sister. The night of their return, the oldest son was roused from his sleep by a commotion only to discover that his younger sister was actually a murderous fox spirit who had devoured the rest of the family so as to become a human for real.