In Norse mythology, Gunn was one of the Valkyries. Together with Rota and Skuld she attended the battle fields and chose those who were to be slain and taken to Valhalla. She is mentioned on the Rök Stone and in Snorri Sturluson's Edda.
The valkyries' purpose was to choose the most heroic of those who had died in battle and to carry them off to Valhalla where they became einherjar.
Moreover, artistic licence permitted the name Valkyrie to be used for mortal women in Old Norse poetry, or to quote Snorri Sturluson's Skáldskaparmál on the various names used for women: Woman is also metaphorically called by the names of the Asynjur or the Valkyrs or Norns or women of supernatural kind.
In the second and third lays, the valkyries are led by Sigrun, who is the daughter of King Hogni; she marries the hero Helgi Hundingsbani and bears him sons.
A primary function of the valkyries is indicated by the etymology of the word valkyrja, a compound of valr (carrion) and a nomen agentis based on the verb kyrja (to choose).
Gunn and Rota [two valkyries] and the youngest norn, called Skuld, always ride to choose who shall be slain and to govern the killings”.
Whereas the wolf was the valkyrie's mount, the valkyrie herself appears to be akin to the raven, flying over the battlefield and "choosing" corpses ([1]).