how did you react when he came and started to bite you? did you try to move away from him? did you try to back away, or run away, or just push him off?
had you done anything to invite him over, such as hand feed him?
such apparently unprovoked aggression does have to be dealth with, and whether or not it can be changed will depend on the trainer (you or a pro) and the temperament of the pony himself.
like others have said, aggression from equines cannot be indulged nor fled from (except where you fear for you life). you have to stand up to it right away, with a lot of obvious bluster, so the pony gets the message real clear.
the nice part is that he isn't as big as a hrose. a horse rearing at you is a LOT more intimidating than a pony.
you need to chase him off if he comes close. I'd start by moving him off any time he came near, just to establish the FACT in his mind that you ARE capable of moving him around any time you want to. once he knows you can move him, he may not approach you uninvited at all, but if he does, and he proceeds to bite, you'd get after him immediately.
no, you don't let him get to the actual biting stage . you see his little ears pin back, and his mouth get tight and mean looking and his face go all stink-eyed, you then go move him off pronto! you address the mere though in his head of biting you.
you can have a whip, (one long enough to keep you at a safe distance), or a rope that you can swing the end of it in a propeller fashion. I have used my hat, if that's all I had. I take it off, step toward the hrose in MY aggressive manner, and wave it toward his face. beleive me, they move off.
just be very aware of staying toward his head, not his hind. if he swings toward you, and you CAN, whale on his hind end with the rope or whip, becuase he's THINKING about kicking you, and that's all he needs to do for you to get in there and interrupt that bad thought with a rope swinging at him, or on his hiney.
it's not so important that you do hit or not, but rahter that you do something big and hard, and loud enough that it startles him out of that bad thinking.
and don't ever back away . push HIM away! (with the pressure from your whip or rope)