The Mythology & Folklore Database
One day a maiden, passing across this stretch of ground at nightfall, began to sing all the songs she knew, to beguile the loneliness of the way and inspire her with courage. Having soon come to the end of her scanty repertoire, she carelessly sang a mocking ditty about the Herwisch, who, enraged at her impudence, came rushing toward her threateningly brandishing his tiny lantern.
With a cry of terror, the girl began to run, closely pursued by the sprite, who, in punishment for her derisive song, napped his wings in her face and frightened her so badly that she became an idiot.
Since then, the young people of Germany have never dared to sing the mocking refrain, and carefully avoid mentioning the Herwisch's name after nightfall, lest they should in some way arouse his anger.