Lycanthropy is a medical disorder in which a person believes that they can transform into a wolf or wolf-like creature. (TXF: "Shapes") It is often erroneously connected to hypertricosis. (TXF: "Humbug")
In 1994, Scully believed that Joseph Goodensnake might have suffered from medical lycanthropy, when in fact he was a manitou. (TXF: "Shapes")