Wasau (was au) is the spirit made present in the modelled pottery heads of the same name, displayed on ceremonial platforms during the Kwoma yam-harvest ceremonies. In the myth of the pottery clans the wasau is the being that the ancestor Sopermel carried in his belly. The term also denotes the yam-ceremony spirit-head more generally: among the neighbouring Nukuma and Yasyin-Mayo peoples wasau is used where the Kwoma speak of yena, and museum records pair the two names for the same class of object.