In 2004, a 1½-year-old was being seen that had a third antler, much like the buck in the OP. As the ranch owner, I thought we ought to see what became of him.
By the time he turned five, he was one smart cookie. I was probably the last one to see him, about 10:00 during mid-November, he walked within 35-yards of my tower blind to scent check a feeder upwind. Honestly, I almost shot him, but I had a young lady coming out that afternoon for her first hunt, and I thought he would make a memorable first deer. We never saw him again. Two and half years later, I found him deer along a dry creek bed about 80 yards from where this picture was taken. It was just his skull, the antler size and not been much that last year, but the extra antler was still there. I let him rest in peace right where he was.