God Mimir
The god Mimir appears in Norse mythology around the time of the first Aesir-Vanir war as one of the hostages exchanged between the warring parties as a sign of truce. Mimir was one of the gods who went to Vanaheimr in exchange for the gods Njord, Freyr, and Freya, who in turn went to Asgard. He is the primordial and the immortal memory of all the Nine Worlds.