The ethnonym 'Yanomami' was produced by anthropologists on the basis of the word yanõmami which, in the expression yanõmami thëpë, signifies 'human beings.' This expression is opposed to the categories yaro (game animals) and yai (invisible or nameless beings), but also napë (enemy, stranger, 'white'). The Yanomami trace their origin to the copulation of the demiurge Omama with the daughter of the aquatic monster Tëpërësiki, owner of cultivated plants. Omama is attributed with the origin of the rules governing contemporary Yanomami society and culture, as well as the creation of the auxiliary spirits of shamans: the xapiripë (or hekurapë). The son of Omama was the first shaman. Omama's jealous and malevolent brother, Yoasi, is the origin of death and all the world's ills.