Azar is the guy who kills puppies. Literally. When Ted Lavender adopts a puppy, Azar straps it to a mine, explodes it, and then completely fails to understand why everyone is mad at him. Yeah. He's that guy.
Azar is the ultimate macho man. He's always bragging about how tough he is, or saying incredibly insensitive (but occasionally hilarious) things, or pulling an insane prank on a fellow soldier. In a book that's all about ambiguity, Azar shows the capacity for self-awareness exactly once, when he feels guilty for cracking jokes about Kiowa's body.
Azar is the guy O'Brien goes to when he's sunk so far into moral decay that no one else will help him. Azar, who might not even know what the word "moral" means, and who would almost certainly have no truck with it if he did, obviously agrees to help him scare Bobby Jorgenson. But when O'Brien decides to pull out, Azar goes through with the prank anyway and then kicks O'Brien in the head for being weak.
But here's the thing. Despite his whole manly-man thing, Azar is not particularly respected by the rest of the platoon. Sure, they know he pulls these crazy stunts, and occasionally he's hilarious... but mostly they're disgusted by the things he does and says.