Valkyries

The Valkyries were female virgin warriors who armed with helmets and spears rode upon horses. It was their decision who fell in battle, there would be six to thirteen Valkyries present at any single moment. They would take half  the selected dead to Valhalla whilst the other half would go to Freya's afterlife in Folkvangr. Freya would choose the half she wished from the fallen Vikings. Odin would grant the Valkyries permission to enter Midgard in the form of a white swan, but should they be seen out of that form they would become mortal and would never be able to return to Valhalla. The most famous of the Valkyries was Brynhildr whose name means Bright Battle.

(Image Source; http://www.viking-mythology.com/)