Thorondor is the great eagle who rescues Beren and Lúthien in Tolkien’s legendarium.
Beren and Lúthien enter Angband, the fortress of Morgoth, during their quest to take a Silmaril from the Dark Lord’s crown. After Lúthien’s power puts Morgoth into an enchanted sleep, the couple escapes, but Beren is badly injured. Thorondor, lord of the Eagles, carries them away from danger.
Thorondor is distinct from Gwaihir, the chief of the Eagles who assists Gandalf and others in The Hobbit and The Lord of the Rings. Landroval and Meneldor are also named Eagles in the Third Age. Thorondor belongs primarily to the First Age stories and is described as the mightiest of the Eagles.