The pediatric clinical entity called Mater Puerorum appears first in the latin translation of Rhazes' Practica Puerorum and in his Continens. His descriptions of the disease could give some likeness either to a diagnosis of night terrors, or of hyperpyretic convulsions, or of a slight form of epilepsy. Mater Puerorum is afterwards described by most pediatric authors till the Renaissance period without much originality, Rhazes being one of their main sources anyway. Mater Puerorum has been considered by Still and Radbill as a synonym for hysterical fits in children. Going back to the Arabic original naming: Ummu's Sibyan, we venture another etymology based on Babylonian-Judeo-Arabic demonology. The Mother of the Children could be the female demon Karinao—or Lilith—which is said to come to plague the children at night. The naming Mater Puerorum could thus be ascribed to a folklore origin, rather than to hysteria.