Although the various vark subspecies are key components in the Mutant Future food chain, most predators know to give haarmvarks a wide berth. Their garish coloration and surly disposition serve as warnings that they are no easy prey.
Haarmvarks don't excrete; instead, they metabolize waste by turning it into a toxic, oily vapor that can be discharged from nodules on their backsides. This spray—a Class 7 poison—forms a 20' diameter cloud around the haarmvark, and anything caught within takes 7d6 damage each round until the poison dissipates 2d4 rounds later; furthermore, the target is blinded for 2d6 rounds. (A successful Saving Throw Versus Poison results in half damage, and blindness for 1d6 rounds.)
Not only are haarmvarks immune to their own toxin, they are also resistant to all known poisons, diseases, and radiation.