The guy version of a "bridezilla." Usually reserved for the best man, whose pursuit of the perfect bachelor party turns him into a jerky tool-knob.
Kevin was so annoying with the bachelor party preparations. What a brozilla. All I wanted to do was eat a steak and help some stripper pay for law school.
A variation on this would be "Groom-zilla" like my brother was right before he got married. He was quite the grouch.