In the book, Beowulf, Grendel and his mother are the main antagonists. From Beowulf’s point of view, Grendel basically marches into his hall, massacring many of his men, until Beowulf can pin down Grendel and rip off his arm; Grendel then runs away and dies. Later on, Grendel’s mother wants revenge on Beowulf, so she sneaks into Beowulf’s hall, retrieves Grendel’s arm, and abducts one of Beowulf’s men. So Beowulf goes to her lair, defeats her, and lives happily ever after until the dragon kills him, but that does not affect this essay.