Modern Day Grendel

Grendel being a destructive "monster" and killing for the sake of killing relates to modern day natural disasters. Like hurricanes, tornadoes, and earthquakes, Grendel's slaughter of Hrothgar's people is unavoidable; it is unavoidable fate. Especially according to the dragon, Grendel's purpose is to cause terror and thus evoke religion, art, and the furthering of the society of men. He does not kill necessarily to right the wrongs committed by men, but because it is his destiny to destroy. Natural disasters don't occur to avenge the wrongdoings of society, but just purely because that's what happens. Grendel, like natural disasters, kill without direct intention, but are unavoidable, needed, and ineffable things. Precautions can be made to lessen the death toll (evacuation and shelters in the case of natural disasters, warriors like Beowulf and Hrothgar's men in the case of Grendel) but ultimately the occurrence is going to take lives. It's only fate.