Valkyries were maidens in Norse mythology which escorted heroes slain in battle to Valhalla.
Valkyries existed in the Land of Fiction, some of whom were converted into Cybermen, their wings replaced with jet engines. (AUDIO: Legend of the Cybermen)
The Tenth Doctor encountered Valkyries in a recreation of Valhalla. (COMIC: Space Vikings!)
Other references Edit
On Dark Space 8, both Melanie Bush and Commentator Logan referred to Queen Angvia as a "Valkyrie" due to Angvians' similarity in appearance to them. (AUDIO: Bang-Bang-a-Boom!)
Beowulf believed that Ace as a Valkyrie. (AUDIO: Black and White)
Olaf Eriksson mistook Tamsin Drew for a Valkyrie. (AUDIO: The Book of Kells)