The Mearas were a breed of wild horses in the north of Middle-earth. The Mearas were one of the fastest breed of horses of Middle-earth. Their mortality is equal to Men and their intelligence and strength are extraordinary.
They were descended from Felaróf, who was tamed by the first King of Rohan, Eorl. Ever since, they have been the mounts of the King and Princes of Rohan alone, the sole exception being Gandalf the Grey who rode Shadowfax, Lord of the Mearas, during the War of the Ring.