What makes a monster?

I agree that Grendel is the monster in this story, but I think he displays more human qualities than monster qualities. For example, he often allows his emotions to get the best of him, rather than proceeding with purely evil intentions especially in the earlier stages of his life. The novel opens by showing Grendel's fear and anger--very human emotions. Gardner writes, "The old ram stands looking down over rockslides, stupidly triumphant. I blink. I stare in horror." (5). The notion of a massive, incredibly strong creature such as Grendel being afraid of a ram is ridiculous. This, however, shows that although Grendel certainly has the capability to be a monster, he often forgets this and shows human emotion, like fear. In addition, during his childhood Grendel displays many of the same characteristics as teenagers. When Grendel is between two tree trunks, he is worried about missing his curfew and calls for his mother, much like a teenager would do. Likewise, this dependence on his mother shows that Grendel is not yet mature enough to be independent. Because of this lack of maturity, I do not think it's fair to call him a monster. Monsters are creatures that knowingly commit acts of evil, purely for evil purpose. Due to Grendel's lack of ability to function by himself, it is clear that he is not mature enough to truly think through all of his actions. Grendel will, however, eventually grow up and be responsible for his actions, but at this point in the novel (about a quarter of the way through), it is unfair to call Grendel a monster.