Usually used in a workplace setting. Defines someone, usually management level, that comes into a big project at the last minutes and changes things for the worse, thereby ruining the project.
"Dammit, the ten of us have been working day and night for the last two weeks on that presentation. Then that swoop fucker shows up the afternoon before the meeting and took out all the good parts."
von Dwardisimo Rex 25. August 2006