As per the epic of Beowulf,Grendel is shown as a coward,a monster,and an insensitive character.
Grendel was referred to as ""spawned in that slime"a biblical allusion to the story of Cain and Abel.
Grendel symbolises the sin of a man/woman,especially from greed.Grendel was the son of Abel.Grendel was condemned by God because of the dispute between Cain and Abel.