Character is still going there initial development. (Thus the sketch-grade artwork!)
Put simply, you can't tell who his friends are because he will get angry at anyone. Well, except Mikey. He made the mistake of punching him once, earned him a full-force punch from Daniel. Strong, short tempered and aggressive, you will regret it if you cross him. And funny thing, He is Mike's best friend. But, Mike will make friends with any big jock who'll sit on him, so no surprise there. even though Felix is really rough with Mike, whether or not he's being playful.