Also called 'the Windlord', Gwaihir was an eagle of the Misty Mountains. He was the largest and most powerful Eagle of his day, the King of All Birds and a special friend to the Wizards and Elves, particularly after Gandalf healed him of a poisoned wound.

During the Quest of Erebor in 2941 of the Third Age, Gwaihir and his Eagles rescued Thorin Oakenshield and company from an Orc attack. During the Battle of Five Armies before the mountain Erebor, Gwaihir and his Eagles played a critical role in turning the tide of the battle.

During the War of the Ring, Gwaihir freed Gandalf from Isengard, and later carried him down from the peak of Zirak-Zigil after the battle with the Balrog.

During the last battle of the war, before the Black Gate of Mordor, Gwaihir and his brother Landroval led all the Eagles of the North against the Ringwraiths, just as the One Ring was being destroyed.

Then Gwaihir and his brother flew to the slopes of Mount Doom where they rescued Frodo Baggins and Samwise Gamgee.
Encyclopedia entry originally written by High_King_Of_Gondor