Person who try to stuff massive amounts of luggage, bags, gifts, coats, and other crap in the overhead compartment of the airplane. The most egregious overhead-hog is one who attempts to put all of his/her stuff only in the overhead compartment above their own seat--even though that particular compartment might already be full.
"That obnoxious overhead-hog held up the line while trying to stuff a bunch of Christmas packages in the space above his seat. It was clear that the packages wouldn't fit!"
by David E. Woodard February 1, 2007