 "Even a man who is pure at heart, and says his prayers by night, may  become a wolf when the wolfbane blooms and the autumn moon is  bright." This quote has been listed in some sources as an authentic  Gypsy or Eastern European folk saying. Writer Curt Siodmak (qv)  admits that he simply made it up. Nonetheless, the rhyme would be  recited in every future Universal film appearance of the Wolf Man,  and would also be quoted in _Van Helsing (2004)_ (qv). (Albeit,  slightly modified, "The moon is shining bright." rather than "The  autumn moon is bright.")