How do I get rid of this guy?

Okay I'm going to be totally honest right now, and I'm not trying to be a jerk or put anyone down. But I need to be truthful here. There's a guy in my class that obviously likes me (I'm 15 he's 16? Maybe?) He might have a condition, but he has a hairline that goes so far back it seems like he's balding. He also has a high squeaky voice and a lisp, buck teeth, and he smells like BO. he constantly talks about porn and girls and it annoys the crap out of me. he thinks it's so impressive that he's been in fights, and he thinks he's all that and a sack of potatoes. I know a lot of people act conceited because their unattractive or have insecurities. But he's literally just full of himself. he thinks he's so clever and so tough and manly. He tries to be near me, and is always practically breathing down my neck and keeps trying to be close with my friends and stuff. I'm not hot either though. People think I have a pretty face, but I'm obese and idk why any guy would like me...but he does, and overall it's not even about the looks. I've liked unattractive guys with amazing personalities, but he's just a jerk. he cusses out teachers, and tries to make me side with him, and he never thinks he's wrong. I tried being friends but he thinks I like him or some crap, and idk how he got that idea. Because after a while I honestly stopped talking to him when he's tried to talk to me. I'm so done. How do I handle this? Again, I'm not trying to be rude, I'm just tired of this jerk of a guy.