They spend their days finding ways to nitpick, second-guess, and generally undermine any and all efforts to improve the office environment.
They're a special kind of critic - always looking for the smallest of flaws, and never willing to accept anything less than perfection.
We ignore them, occasionally send them to a time-out room, and wonder how they've managed to thrive in the wilds of corporate bureaucracy.
We're not sure, but we're working on it.