Ao Ao is the name of a monstrous creature from Paraguayan mythology. As one of the cursed sons of Tau and Kerana, it is one of the central mythological creatures among Guarani-speaking cultures. The Ao Ao is often described as being a voracious sheep-like creature with a massive set of fangs. Alternatively, it is also described as being a large, carnivorous peccary. Its name is derived from the sound that it makes, howling "Ao ao ao!" when it is pursuing its victims. The original Ao Ao is said to have profound reproductive powers and thus sometimes is identified as being the Guaraní spirit of fertility. Ao Ao produced many offspring who are cursed in the same manner, and collectively they served as lords and protectors of the hills and the mountains.