Hasufel

In compensation for the presumed deaths of Merry and Pippin, Eomer gave Legolas the horse Arod, and gave Aragorn Hasufel.

He rode it across much of the plains of Rohan but the creature fled in fear with Arod when an old man (Most likely Saruman) came to where the Three Hunters we're camping to spy on them. The horse returned with Shadowfax some time later.