The myths of the people of ancient Iran contain references of many animals and among them the horse is of particular importance. In mythological terms, the horse appears as the symbole of the warrior class. In the beliefs of the people of ancient Iran, the connection between the horse and the warrior was related to the ambiguity of the horse. In the Avesta, this is shown by the use of -aspa (horse) in proper names and in the opposition of the white horse and the black horse.Studies in ethnology show that the horse is frequently connected with deities of the wind. It is not unusual, for example, for a horse to serve as a sacrifice to the deity of the wind. In the Avesta, too, passages hinting at the ties between horses and the wind can be found. In Zoroastrianism, wind possesses opposing qualities. Vayu, the god of wind, presents a clear duality. The twin Mainyus of good and evil reside in Vayu, like Zurvan.Wind is the demarcation between life and death, situated between this world and the after life, as demonstrated in the Haδoxt Nask and the Aogemadaeca. The horse, too, represents the character of being this boundary or being situated in the between. This point can be seen in the horse as a metamorphosis of Verethraghna as well as the Gushnasp fire venerated during the Sassanian dyansty. The proof for the tie with the boundary is the prayer on horseback frequently mentioned in the Avesta.