That douche bag that goes to classes with a gallon jug of water or some other liquid. The need for this kind of hydration in a class that at most will be in session 3 hours, is excessive for any human being, even Michael Phelps.
"That guy brought a gallon of water to ENG 101? Really? What a Gallon Douche"
"Man, that guy looks like such a douche carrying that gallon of water across the quad. We should call him a Gallon Douche"