How about " Uncle Buck " , I think that was a movie with John Candy, comedian. Or Buckshot, Buckaroo, May Buck, or if you're old enough and have this sense of humor Buck- U . He'd still hear a name he's familar with but it shakes it up some. I had a QH years ago named Bay Line Buck, one of the best, maybe the best horse I've ever owned. Have fun naming him, he looks great!