One who is the combination of a pessimist and a douchebag. Usually has a constant annoying, negative outlook on life and anyones ideas except theirs. If told they are a pessimist, they will usually try to play it off by being even more of a pessi-docuhe.
Serious cases of pessi-doucheness may result in the argument of how .999...=1 when clearly no one gives a fuck, a constant reminder of some past-argument which had something to do with their pessi-doucheness, or the rejection of hanging out with babes because they think it wont be fun
George "Hey lets go to that party tonight, theres gonna be a bunch of hot girls there, sounds awesome."
Charlie "Nah that doesn't sound too fun, lets just chill here and do nothing for another 4 hours."
George "God dam it your such a pessi-douche."
Charlie "No im not! Your the one with the stupid ideas."