What is the name of the hawk between the eagle's eyes on Yggdrasil?

The hawk between the eagle’s eyes on Yggdrasil is Veðrfölnir.

The detail comes from Snorri Sturluson’s Prose Edda, specifically Gylfaginning. An unnamed eagle sits high in Yggdrasil’s branches, and Veðrfölnir rests between its eyes. The eagle is said to possess great knowledge, although the surviving sources do not clearly explain the hawk’s own role.

Veðrfölnir is easy to confuse with other animals associated with the world tree. Ratatoskr is the squirrel that carries hostile messages between the eagle and Níðhöggr, while Níðhöggr is the serpent or dragon gnawing at the roots. Hræsvelgr, by contrast, is a giant associated with an eagle-like form, not the hawk perched on Yggdrasil’s eagle.

The name is usually interpreted along lines such as “storm-pale,” “wind-bleached,” or “wind-witherer.” Unlike the eagle, which appears in both the Poetic Edda and Prose Edda, Veðrfölnir is specifically attested in the Prose Edda account.