I used to ride a horse like that! Except he would also pretend he was going to attack you! Lol He would pin his ears and rush at you and throw his rear end towards you. Obviously, he was just faking me out and I knew how to handle it, but it was nerve racking.
What I did was just slowly follow him around at a walk with my shoulders slightly slouched, so I wasn't coming at him with all this agressive energy, with my head down. After about 5 minutes, he would just turn around and wait for me to get him because he realized I wasn't going to play his game.
When that started we began bringing him in more often just to groom him, or give him a special treat. Just to show him that when we brought him in it didn't always mean he was going to get worked. Because previous to that, that's all that happened. The girl that was shareboarding only came out like once a month and then worked him. And his owner never came out, so he hated coming in!
I realize that won't work for every horse, but I thought I'd share anyways! Running around sounds so much more fun! :)