My brother is a total jerk and @sshole?

I'm 20 and he's 22. We have never been really close and we used to fight a lot (physically). Though we no longer hit each other we still do not get along. He always put me down and makes fun of me. He says he does it because I have no friends (I have some) and I act immature. He thinks he' mature, but he's a heck of a lot worse than me. He tried to wipe his boogers on me (he did that to his gf too) and was spitting ice at me in a restaurant. He's broke, but my mom does buy him things. He is so greedy w/the snacks that my mother pays for (he chugged an entire carton of chocolate milk so that we only got half a cup). I don't get in his way, but he goes out of his way to bug me. What can I do? Wtf is his problem?