For 12 long years, Grendel attacks the dining hall of King Hrothgar and kills countless Danes. Grendel, an evil demonic monster, tears his victims limb from limb and devours them each night. Grendel can't be harmed by any weapons or swords. He is destined to continue his rampage until Beowulf, the hero, challenges him to a wrestling match. The anonymous writer of Beowulf describes Grendel and Grendel's mother as descendants from Cain who in the Bible kills his brother, Abel. In the biblical story, Cain is exiled to wander the earth and his descendants are considered evil. Grendel is just one of the monsters formed by Cain's sin of killing his own brother.