In many ways, Grendel is the most interesting character in the epic poem Beowulf
. He is a mix of man and beast; his fury is based on very human feelings of resentment and jealousy.
The ogre Grendel is a huge, powerful descendant of the biblical Cain, the son of Adam and Eve, who killed his brother Abel out of jealousy. Cain's name in Hebrew is Qayin, meaning "creature,' and according to legend, the monsters of the earth are his descendents.
Grendel is envious, resentful, and angry toward mankind, possibly because he feels that God blessed them but that the ogre himself never can be blessed. Grendel especially resents the light, joy, and music he observes in Hrothgar's beautiful mead-hall, Heorot.
Although Grendel looks something like a man — having two arms (or claws), two legs, and one head — he is much larger and can defeat dozens of men at a time. He is protected from man's weapons by a magic charm. He devours some of the dead on the spot and carries others back to his lair, the cave he shares with his mother beneath a pool of water in a dark swamp. (Sounds like a wicked video game villain, doesn't he?)