(n.) One who destroys, ruins, kills, or desolates.

animal annihilator anthropophagite arsonist bane barbarian battleship battlewagon beast biblioclast bomber brute burner can cannibal capital ship demolisher despoiler destruction dynamitard dynamiter exterminator hun hyena iconoclast idol breaker idoloclast man-eater nihilist ruin ruination ruiner savage shark syndicalist terrorist tiger undoing vandal wild man wrecker