Which giant takes the form of an eagle and creates the wind?

Hræsvelgr is the giant who takes the form of an eagle and creates the wind. In Norse cosmology, his wingbeats explain a natural force that otherwise seems mysterious.

Hræsvelgr is a jötunn whose name is commonly translated as “corpse-swallower,” though other interpretations have been proposed. His role appears in Vafþrúðnismál, one of the mythological poems of the Poetic Edda. When Odin asks where the wind comes from, the wise giant Vafþrúðnir identifies Hræsvelgr as its source.

Snorri Sturluson expands the image in Gylfaginning. Hræsvelgr sits at the northern end of the sky in eagle form, and winds arise beneath his enormous wings whenever he spreads them to fly. The story turns weather into the movement of a gigantic supernatural being.

Hræsvelgr is easy to confuse with Þjazi, another jötunn associated with eagle imagery. Þjazi transforms into an eagle during the abduction of Idunn, but he is not the wind-maker. Ymir is a primordial being, while Surtr is linked chiefly with fire and Ragnarök.