Gavaevodata () is the Avestan language name of the primordial bovine of Zoroastrian cosmogony and cosmology, one of Ahura Mazda's six primordial material creations and the mythological progenitor of all beneficent animal life.
The primordial beast is killed in the creation myth, but from its marrow, organs and the world is repopulated with animal life. The soul of the primordial bovine – geush urvan – returned to the world as the soul of livestock. Although geush urvan is an aspect of the primordial bovine in Zoroastrian tradition, and may also be that in the Younger Avesta, the relationship between the two is unclear in the oldest texts.
Although Avestan gav- "cow" is grammatically feminine, the word is also used as a singular for the collective "cattle". In English language translations Gavaevodata is often referred to in gender-neutral terms as "primordial ox". Other translations refer to Gavaevodata as a bull and is similar to the Egyptian God Apis. The -aevo.data of the name literally means "created as one" or "solely created" or "uniquely created".
Gavaevodata is only alluded to in the surviving texts of the Avesta, referred to by name in only two hymns. In other instances, for example in Yasht 13.85, the primordial beast is mentioned among the six material creations, but not by name. Elsewhere, such as in the Gathic Avestan Yasna Haptanghaiti, prayers are offered on behalf of the soul of the cow (geush urvan), or worship is offered to "the cow's soul, and to her created body", but in neither case is Gavaevodata mentioned by name, nor is it clear (unlike in Zoroastrian tradition) whether the soul of the cow is the soul of Gavaevodata.
This is also the case for The Cow's Lament. In this allegorical text, the soul of the cow (geush urvan) despairs over the wretched condition to which the forces of deceit (druj) have subjected her (see myth, below), and over her lack of protection from an adequate herdsman. The divinities hold council, and decide that Zoroaster is the only one who can alleviate her condition.