Gello

Gello (Ancient Greek: Γελλώ), in Greek mythology, is a female demon or revenant who threatens the reproductive cycle by causing infertility, miscarriage, and infant mortality. By the Byzantine era, the gelloudes (γελλούδες) were considered a class of beings. Women believed to be under demonic possession by gelloudes might stand trial or be subjected to exorcism. Gyllou, Gylou, Gillo, or Gelu are some of its alternate forms.