Final answer:
In the poem 'Beowulf,' Grendel is a descendant from the line of Cain, the first murderer in biblical accounts.
Step-by-step explanation:
In the poem Beowulf, Grendel is a descendant from the line of Cain, mankind's first murderer. This connection is established early in the text and is significant as it frames Grendel as an inherent embodiment of evil, descended from the biblical figure known for committing the first act of murder.
This lineage explains the monstrous character's malevolence and his antipathy towards the humans in the poem, who are protected and favored by God, whereas Grendel's lineage is cursed.