Eikþyrnir

Old Norse eikþyrnir = 'the one with the oak-like antlers' (see also EIK and ÞORN)

Eikþyrnir is the name of the stag which stands on Valhalla's roof and grazes from the leaves of the tree called Læraðr (= Yggdrasill?). Drips of water coming from the tips of his antlers fall into the spring Hvergelmir, which feeds all the rivers of the world.