Until 1486, two clerics, James Sprunger and Henry Cremer, co-authored a book called "Witch's Hammer." The beginning of the book warns readers that witches are heretics and details how witches copulate with demons, eat human hearts and livers, dance madly, indulge in lust, and so on; how they obstruct fertility, seize male reproductive organs, kill infants in the cradle in different ways, harm livestock, cause hail and storms, and strike humans and animals with lightning, among other forms of damage. It finally explains the procedures and methods of witch trials and judgments.
For example, the book describes the method of identifying witches like this:
