The Malleus Maleficarum is a witch hunters guidebook written in 1486 by a pair of German inquisitors with considerable expertise in the matter. It contains concise instructions on the handling of witches and detailed description of their power. Most interesting (at least to me) is the section entitled Whether Witches can Hebetate the Powers of Generation or Obstruct the Venereal Act. An excerpt below:

Now the fact that adulterous drabs and whores are chiefly given to witchcraft is substantiated by the spells which are cast by witches upon the act of generation...[T]hey can take away the male organ, not indeed by actually despoiling the human body of it, but by concealing it with some glamour...[I]t must in no way be beleived that such members are really torn right away from the body, but that they are hidden by the devil through some prestidigitatory art so that they can be neither seen nor felt. And this is proven by the authorities and by argument...

And what, then, is to be thought of those witches who in this way sometimes collect male organs in great numbers, as many as twenty or thirty members together, and put them in a bird's nest, or shut them up in a box, where they move themselves like living members, and eat oats and corn, as has been seen by many and is a matter of common report? It is to be said that it is all done by devil's work and illusion, for the senses of those who see them are deluded in the way we have said. For a certain man tells that, when he had lost his member, he approached a known witch to ask her to restore it to him. She told the afflicted man to climb a certain tree, and that he might take which he liked out of a nest in which there were several members. And when he tried to take a big one, the witch said: You must not take that one; adding that it belonged to a parish priest.

These parish priests sure think the world of themselves.