A metaphysical device that functions by taking taking perfectly good situations and turning them to shit.
While fecalators have never actually been seen, such devices must exist in order to explain situations where everything seems to go to Hell.
Alphonse: "Hey, Gaston! Is the copier up?"
Gaston: "Naw. Someone must of left the fecalator on."
Big, intimidating gun.
Gun Salesman: We call this next item "The Fecalator." One look at it, and the target shits his or her pants.