PUFFIN

From the bicycling world in England. Refers to "Pathetic Unfit Fat F&%$ers In Nappies". Its a derogatory term used to refer to how out of shape cyclists look in their cycling kits. The term is a more extreme version of the term MAMIL ("Middle Aged Men In Lycra"). The earliest use of the term is in 2013 in an article by Alexei Sayle in The Telegraph.

The poor guy doesn't realize that when he's on the road in his cycling gear he looks like a classic PUFFIN.