Umm es-Sibyan, the 'Mother of the Children,' is the child-snatching jinniya of the desert spirit-world, a demoness known across the Arab lands and firmly established in the beliefs and amulet practice of the Bidan. Despite the maternal name, she is the enemy of mothers and the newborn: sources attribute to her miscarriage, the convulsions and wasting of infants, and the deaths that shadow childbed, and in this she is likened by scholars to Lilith and the Lamia. Against her the marabouts of Mauritania compose the hirz, the written charm inscribed with Quranic verses and the names that bind her, worn or hung above the cradle and the woman in labour. She belongs to the great class of the jinn that populate Bidan cosmology, but stands out as one of the few individually named beings among them, invoked and repelled by name in the everyday esoteric science of hjab.