joke buzzard
An individual whose comedic timing leaves much to be desired. A joke buzzard will absorb a joke, process it, and sit on it...until three months after the joke ceases to be funny, when the J.B. will swoop down with an unfunny joke like a hawk on crack and killing any conversation in its path.
A Rosie O'Donnell joke? Seriously? This guy's a freakin' joke buzzard. There are buildings younger than that lame one-liner.