Legends of wolf-men exist in the beliefs of almost all peoples and cultures. The terror of werewolves reached a climax in the late Middle Ages when Kramer's Malleus Maleficarum (Hammer of Witches) linked the creatures to religious heresy, Satanism, and witchcraft.  He described the wolf-man transformation as the result of malevolent witchcraft and presented shapeshifting as a common, demonic practice.  Baring-Gould's study on werewolves successfully manages to compress an enormous span of historical material into his work. The book is valuable to academics, those interested in folklore, and any wishing to learn more about the occult.