Porcupines

To imagine an animal that is completely offensive, that is, completely capable of hunting, killing and eating you in a multiplicity of ways, would be to imagine something like a leopard, a hawk, or a giant snake - or the conglomerate of all three, a dragon. Conversely, to imagine an animal that is completely defensive would be to conjure the morphology of a turtle, a snail, or perhaps even a porcupine. Subtract the quills, and a porcupine is merely a plump groundhog, ripe for the pickings of a variant of ground predators. Keep the quills and a porcupine is a formidable biological fortress, like a Roman army phalanx; formidable, but not impenetrable. A good few whacks from the club of a tribesman is sufficient to end the cardiovascular circulation and neurological activity of any husky porcupine. Their defense mechanism is excellent against a majority of attack protocols, but renders them virtually defenseless against the proper attack. Much the same is the defense mechanism of the powers of darkness in the spiritual realm - and their defenses will not prevail.