Eagles
The Eagles of Middle-earth were immense, sapient birds that could speak. They resembled actual eagles, but were much larger than any creature that exists today. Thorondor, the greatest of all eagles, had a wingspan of 30 fathoms (55 meters).
The Eagles were often used as agents of eucatastrophe or deus ex machina in Tolkien's stories. They would swoop in at the last moment to save the day, often carrying the heroes on their backs.
The Eagles were not always seen as benevolent creatures, however. Bilbo Baggins, the protagonist of The Hobbit, feared that he would be torn apart and eaten by the Eagles. And in The Lord of the Rings, the Eagles are said to have carried off children from villages in the Shire.
Despite their fearsome reputation, the Eagles were also seen as symbols of hope and freedom. They represented the power of nature to overcome evil.