For wizards, "Painted Skin" has two meanings.
One is a rare magical tool, and the other is a mysterious magical creature.
The former is made from human skin, beast skin, and so on, with the skin intact, including hair and facial features no different from a living being. When used, one need only wrap it around their body, roll on the ground, and they can transform into the creature represented by the Painted Skin—very few wizards can distinguish it.
The latter is a kind of ghastly demon with emerald faces and jagged teeth like a saw, their cries resembling pig squeals, fond of eating children's hearts. They can peel off the skin of their victims to take on their appearance. Because they are too ferocious, they have been hunted to near extinction by wizards; even students from First University can only see their remnants in specimen form in the specimen room.