Although Beowulf is a hero and Grendel is an antihero, they are actually parallels and have a few similarities. First, they are both outcasts and choose to operate alone. Second, they both are filled with anger as they go into battle: Grendel is offended by the happy men's merrymaking's and Beowulf is offended by the monster and his vicious killing. Third, they are both proud and boastful, though in Beowulf's case he has reason to be whereas Grendel does not.