A person of particular annoyance who seeks out the best opportunities to piss people off. Someone who hides or hangs back during a hectic situation only to jump in at the last minute and attain some glory without any real effort. Someone who frustrates others until they're blue in the face or holds back until they themselves are blue in the face before using minimal effort and attaining maximum payoff. As if they spike themselves into the situation.
"Clinton never does anything around here until it's easy to finish the job."
"Yeah, he just sits back like a blue kirby and watches the others do all the work."