Kumiho
The real definition of the word kumiho is a mythical creature in Korean folklore and legends that is a fox that lives 1,000 years and therefore turns into a kumiho, which, simply put, is a nine-tailed fox. The kumiho can shapeshift into a human whenever it wants, but it may still have fox ears or a fox tail visible as a result of truly being a fox. It has to eat livers of humans to avoid dissolving into bubbles in a thousand years, but a kumiho can become human forever and stop having to eat humans if the kumiho can refrain from eating humans and/or human liver for 1,000 days.
Moonlight shone over a graveyard at night, when all humans are asleep, and in the light you could faintly make out the shape of a kumiho, wandering around the graveyard all alone. Its nine tails stuck up high in the air as it prowled silently around the graves, sniffing the air a few times before coming to a halt in front of one of the graves. It sniffed the air again, then began to dig at the foot of the grave, until the human that had been buried in the ground was unearthed. The kumiho pricked its ears to make sure no one else was nearby, then bent its head down and began to eat its prey.
