Vafthrudnir

Vafthrudnir is the wisest of giants, a riddlemaster whose hall holds the deepest lore of the cosmos. Odin, disguised as the wanderer Gagnrad, comes to test him, and they stake their heads on a contest of knowledge. The giant answers question after question on the origin of earth and sky, the horses of day and night, the fate of the gods at Ragnarok. He loses only when Odin asks what the god whispered into dead Baldur's ear, a thing no one but Odin can know. Recognizing his guest too late, Vafthrudnir forfeits his head in the poem Vafthrudnismal.