1) A very clever sketch performed by the Monty Python boys consisting of a group of blundering cardinals dressed in silly red hats who laugh diabolically and torture unsuspecting english persons with dish-drying racks. Amongst their weaponry are such diverse elements as: fear, surprise, ruthless efficiency, an almost fanatical devotion to the Pope, and nice red uniforms...
2) What nobody expects.
A legit psychopath who has done at least one of these things: barks at you, threatens you, has a criminal record, or is going through a mid-life crisis.