Iron Will is a minotaur, as Putting Your Hoof Down mentioned a myriad of times, so that means he is half man half bull. I am making that assumption considering that is what a minotaur is, and the fact that he is certainly not half pony considering the obvious and the fact that he walks on two legs all the time. Does this really say anything about humans in equestria, or is iron will just half man in a world where that doesn't really make sense? Probably the latter, just wondering.