Battle Unicorn, yes, really, was an autobot who found hmself in the land of Equestria.
After the space bridge incident, he was relocated to Ponyville, Equestria. He had a race with Windblade, Rainbow Dash, and Mach Kick, but did not win.
Behind the scenes
Windhorse is a minor recurring Transformer in the Transformer franchise. A Twilight Sparkle variant color scheme toy of him was shown off in 2014 called "Twilight Sparkle Prime", but never released.