i love how everyone keeps saying "fight back" haha... that's the wrong thing to do! helloooooo!! lol
if it were me, i don't think i'd fight back... because that's exactly what he wants, duh! that would be why he keeps pushing you, because he wants you to fight back so he can then beat your ass, haha =/
i'd probably act like i was above him. because you are above him. you're better than him, you don't run around putting other people down because of your own insecurities. so he obviously has issues of his own. i'd completely ignore it and act like i didn't even hear the words coming out of his mouth, so much that he might start thinking you're deaf or something! haha.. i'm sorry, but to be honest, fighting is the immature route to take. don't you guys understand that fighting is exactly what the bully is doing? uh.. wtf?
anyway, stand your ground in a way that this kid doesn't even know about.. ignore him. don't let it get to you, show him that he holds absolutely no value to you. why the hell should you care what his jolly green giant ass has to say? he means nothing to you, so his words mean nothing to you. maybe tell him that you're sorry he feels that way, haha... he's just a jackass with his own problems, bud.. you'll learn to take people like that with a grain of salt, you might even start to feel sorry for them, haha

best wishes to you!