Arod was a fast, white, noble, strong, fiery, restive horse of Rohan. He was hard to control and seemed to understand the importance of the journeys. After the loss of his original rider, Arod was given to Legolas by Éomer Éadig in compensation for the supposed deaths of Merry and Pippin. Legolas ordered for his saddle and rein to be taken off, and rode him with ease. Throughout much of the War of the Ring, Arod carried Legolas and his friend, Gimli, a Dwarf.
At one point in the story, Arod and Hasufel (horse given to Aragorn by Éomer) are frightened away by an old man (assumed by the characters in the book to be Saruman). They later come back, along with Shadowfax, who has been summoned by Gandalf as his own horse. Arod later accompanied Legolas on his way to Edoras, and aided him with the battle against the Warg riders. Legolas also rode on Arod during their fight in Helms Deep.