The story is a metaphor for the role of women in society. It borrows heavily from Shelley’s Frankenstein, and is not actually as good as it’s supposed to be.
Anti-hero indeed. The ugly-duckling with six inch razor sharp claws and an overbearing mother. Think of a velociraptor in the Anthony Perkins role of Psycho.
Grendel sees himself as sort of a divine punishment sent in response to all of the evils that the humans were guilty of. I liked the book a great deal, especially the ending.