My friend is an arrogant dumb ***?

The guy is obviously being a ******' idiot. It'd be best to avoid being around him for a while. Though, the attitude is pretty concerning. I'd trying talking some sense into the moron. Tell him that he is being a dumb *** and he needs to snap out of it before he gets himself into some ******* trouble. If that doesn't convince him to change, you need to go outside for help. Tell your parents or a teacher or something. Yeah, its sounds like a shitty thing for a friend to do, 'ratting' on another friend like that, but its important to get him help. He might be pissed at you if you do that, but its for his sake, and he'd thank you for it later.