Samdugumi is a creature from Jeju Island’s shamanic narrative (bonpuri), a grave-fox with three heads and nine tails. It disguises itself as a human to prey on a family, and is said to be vulnerable to cast iron and raw eggs.
It is an independent Jeju variation of the fox-shapeshifter tales of the Gumiho lineage. Because it has fixed weaknesses, it shows the structure of Korean creature-defeating lore, in which one confronts the monster by reasoning out its rules and taboos.