A Giantess. Her brother SUTTUNG left her in charge of the Mead of Inspiration. Bad mistake. It may have been hidden in a cave in the middle of a mountain, but ODIN knew his way around, sought her out, and found her in.
He offered her sex in exchange for the Mead. Girls her size and temperament don’t often get offers like that. Yes, yes, yes! The end result was the birth of BRAGI, the God of Poetry and suchlike. See KVASIR.