Context: The informant is a 21 year old USC student. Her dad is Korean and her mom is American; this story was told to her by the Korean side of her family.

The story goes that one day, a boy cut his fingernails and toenails and didn’t dispose of the clippings properly. He threw them outside, where a mouse came across them and ended up eating them. The mouse turned into an evil doppelganger of the boy and when the boy was out, went to his home and replaced him. When the boy came back, he was confronted with another version of him that had essentially taken over his life. He came to his parents and told them this, and his parents, confused, set the doppelganger and the boy next to each other to figure out which one was the original. Somehow, the parents chose the wrong one, and the boy ended up getting kicked out of the house, never to return.

Analysis: The informant told me that the moral of the story was basically that if you don’t dispose of your fingernail and toenail clippings correctly, a mouse will eat them, become you, and ruin your life. This folktale is one that seems dependent on the concept of contagious, or contact-based, sympathetic magic. Here, parts of the boy are not destroyed and so can be used against him; his nails, having once touched him, are believed to still be part of his body to the extent that affecting them can affect the body. Just as the mouse consumed the nails, the mouse-doppelganger consumes the boy’s life, using parts of him to reconstruct the whole. It’s a cautionary tale, reminding people not to make anything that can be used against them public

The informant was unsure how exactly the nails were disposed of incorrectly or how they should have been disposed of for safety purposes. While neither she nor her family practices this, it is apparently a common Korean folktale.