An annoying coworker who thinks that he is an authority on every subject ever conceived. Behavior includes (but is not limited to) butting in to every conversation within ear-shot, complains incessantly, taking over and fucking up other people's projects, picking fights for the sake of fighting, fucking up because he thinks that he knows everything and doesn't need to RTFM
or ask questions to more knowledgeable staff members, invites himself along to lunches and happy hours, brags incessantly, physically stinks of rotten cabbage, and crying whenever something doesn't go his way.
Originally conceived as an acronym for our coworker Sam's bizarro
twin - "Fat, Evil, Melting, and Ugly Sammy."