Meatmagic (Metamagic Feat). You spell only interacts with animal matter. It has no effect on objects made of wood or metal or stone, ignores metal and wood armors, and can shoot through barriers of vegetable or mineral composition (such barriers do not affect cover or line of effect, though they may still impact concealment and line of sight).
+3 spell levels. #Microfeats
(based on an idea from friend Carl!)