Answer :
Beowulf's greatest enemy is no monster but himself and his pride, or hubris. It is his greatest weakness which results in his death. It is predicted or foreshadowed throughout the entire story. Begining with the stories of his youth and then his private conversations with Hrothgar in Heorot. His avarice and obsession for the attention of his friends are the result of his pride, not separate characterstics.
