The fat-boy-cut is a type of haircut that would appear on the heads of fat children in the early to mid 90's. Its a bowl cut placed in a high up position on a completely shaven head. The type that rock the fat-boy cut are usually a couple of guys from your old school, normally the ones that you knew who they were but didn't really know them. For visual aid see Zachery Ty Bryan in a pre-puberty episode of Home Improvement.
"Dude, getting punished by Krampus sucked bad but at least he liked my fat-boy-cut."
Guy 1: "Hey Tom, give ya the usual?"
Guy 2: "Hmmm... no I think i will just have ya give me the fat-boy-cut."