In some love stories and legends, the groom initially appears as a beast and after marriage is restored to a human form. The stories of beast-groom in the West are influenced by the story of ―Cupid and Psyche, ‖recorded by Apuleius, and in Iran by the story of Zahhak‘s marriage to Jamshid‘s sisters. Undergoing displacement, in the Islamic period, the beast-groom story was adapted to the Islamic thought and found a new place in the mystical anecdotes. An example of such stories is included in the book Hezar Hekayat-e Sufeyane.1 The central plot of this story is about the marriage of a werewolf to a human girl. In this paper, after studying the structure of this story and its mythological roots, I have compared it the story of Zahhak‘s marriage to Jamshid‘s sisters in Ferdowsi‘s Shahnameh and some other Iranian legends about beast-grooms. I have, furthermore, studied the symbolism of the wolf in Iranian mythology. Wolf is a manifestation of evil and, at the same time, a totemic ancestor of some neighbors and enemies of old Iran. According to the findings of this study, marriage of a human being to a werewolf in the mystical tales is linked to the exogamy tradition.