I read somewhere Grendel is supposed to be a descendant of Cain (from the book of Genesis). I do not know what you have to mix in down that line to get whatever Grendel is supposed to be, but I don’t think I want to know. The theory that Grendel is a descendant of Cain makes a lot of sense. I feel that in a lot of way Grendel represents several things that are wrong with the world and with society. The selfishness and the “every man for himself” mentality are factor notorious for getting people in trouble even today.
Grendel’s mother reminds me of a drug-addicted parent. She is unable to be there very much for her son, but she obviously still cares and comes running whenever he needs her most.