In northern England blood dogs appear the day after a battle has occurred. They dig into the ground in order to drink up the blood that has pooled there. Described as being massive, gray hounds with red eyes, their panting breath is hot enough to scorch the earth. In some older versions, they are said to look like humans with the face of a dog. Both accounts agree that the blood dogs leave no mark upon the ground regardless of the terrain and in spite of their weight. In Scotland blood dogs are believed to be the ghosts of Bonnie Prince Charlie’s (Prince Charles Edward Stewart, or Charles III) hunting hounds and feed exclusively off English blood.

Source: Hasluck, Unwritten Law in Albania, 256; Luther, Works of Martin Luther, 92; Maberry, Vampire Universe, 46