The Dark Mark is Voldemort’s version of the Devil’s Mark, a notion from the Middle Ages. According to one medieval demonologist, “the Devil makes a mark on them, especially those whose allegiance he suspects. The mark varies in shape and size; sometimes it is like a hare, sometimes like the foot of a toad, sometimes like a spider, a puppy, or a dormouse. It is imprinted on the most secret parts of the body; men may have it under their eyelids or armpits, on the lips or shoulders; women generally have it on their breasts or private parts. The stamp that makes these marks is nothing less than the Devil’s talon.”

Witch hunters often declared scars, birth-marks, warts, or other blemishes to be the Devil’s Mark. Accused witches were shaved completely so that every bit of their bodies could be examined.

In addition to the Devil’s Mark, witch hunters would look for a Witch’s Mark. This was a less serious matter—only the Devil’s Mark signified a special pact, such as the bond between Voldemort and the Death Eaters—but it could still be fatal for the accused person. Every witch was believed to have one. Any blemish, like a mole or large freckle, might be identified as such.

Sometimes the Witch’s Mark was said to be a spot of skin that did not bleed and where no pain could be felt, so accused witches were pricked with pins (called bodkins) as a test. Often, witch hunters were paid only if they found a witch; so many cheated. For instance, they used special bodkins, similar to the trick knives used in magicians’ acts today. The sharp stem would disappear into the handle when pressed against someone, so it would not puncture the skin.