A sharting spider is a particularly heinous sub-specie of the "Barking Spider" in that it's defense method is not just a warning signal and fowl smell, but also warns potential predators with a deposit of substance known by naturalists as 'beware brown'. They are particularly fond of burrowing in 'tighty whiteys'.
subject 1: (Notices subject 2's dirty underwear on the floor) "Woah! Either you never learned to wipe your ass or you were born without a sphincter!"
Subject 2: "What?....No...I'm dealing with an infestation of Sharting Spiders. That wasn't me!"