Gunnlod

A giantess. Gunnlod ("war-summon") was the daughter of the giant Suttung. Gunnlod was the Keeper of the Mead of Poetry. When her father gained the Mead of Poetry, Suttung set her to guard the magic mead in a cave.

When Odin gained entry to the cave, Gunnlod was willing to give Odin a drink of the mead, but he had to sleep with her. So Odin slept with her for three nights, and the god drained all of the mead from the three vessels.