Someone who is short, fat and acts like an asshole.
From personal experience they usually think they have some sort of power and are generally slow. (See chav)
Short Fat Faggot: Hey, what the fuck are you fuckers looking at?
People: A short fat faggot.
SFF: I'll get my crew to bang you out, mate!
People: Your loner crew of other short fat faggots?
SFF: Yeah?... Wait, fuck you!