Brego

Brego was a horse of Rohan.
He was a bay horse with a white star on his forehead and white markings on his hind legs. He was the steed of King Théoden's son, Théodred, who was mortally wounded in battle with Orcs. It is assumed that Brego was brought back to Rohan by those riding with Éomer when he went to rescue his cousin.
After that rider's death, Brego became wild and refused to accept any new rider, until Aragorn met him in the stables of Edoras. Aragorn calmed the horse, speaking to him in Sindarin, then told the stable hands to turn him free, saying ”This fellow has seen enough of war."
On the way from Edoras to Helm's Deep, Aragorn was unhorsed and presumed killed in a battle with Warg riders; however, he fell into the river and floated downstream. Brego found him on the shore of the river and nudged him awake, carrying him to Helm's Deep in time to bring warning of Saruman's approaching army of Uruk-hai.
Brego was ridden by Aragorn to the Paths of the Dead, though he refused to go any further when drawing closer to the door. The two of them were later reunited at Minas Tirith, and Aragorn rode to the Morannon to confront Sauron's forces. Brego's fate is unknown.