Some of Beowulf’s most important traits as an epic hero include bravery, loyalty, honor, superhuman physical strength, and the willingness to risk his life for the greater good. These characteristics are exemplified in Beowulf’s epic deeds, including slaying Grendel and Grendel’s mother. Beowulf later also demonstrates the epic trait of being a just ruler of his people, the Geats, and sacrificing his life to slay the dragon that threatens them.
Beowulf is an epic hero for many reasons. Three of Beowulf's most epic characteristics are strength, honor, and the ability to rule justly.
1) Strength: First and foremost, Beowulf is strong, and is known to possess power greater than any normal warrior. This is evidenced by his ability to wrench off the gigantic Grendel's arm and by his ability to contend with Grendel's equally monstrous mother. In short, Beowulf, like Hercules and Achilles, is far stronger than conventional warriors, and his superhuman abilities elevate him to an epic status.
2) Honor: Beowulf is also described as being honorable and virtuous. This characteristic comes into play many times, but it is most evident in Beowulf's commitment to fighting Grendel in hand-to-hand combat, rather than using man-made weapons. Beowulf reasons that Grendel does not use weapons, and so he will likewise eschew any armament besides his own strength. Thus, Beowulf shows that he follows a respectable code of honor, extending respect even to monstrous foes.
3) The ability to rule justly: Beowulf rounds out his epic qualities by proving himself to be a capable ruler. He clearly does not want power, as he initially refuses the throne of his country and only becomes king when it's clear there is no other option. He then goes on to rule for fifty years, and it seems as if the period of his rule is marked by peace and prosperity. As such, Beowulf is epic not only because he is a skilled fighter, but also because he is capable of justly ruling the kingdom entrusted to him.
There are 4 characteristics that all epic heroes must have - they are Glorified, On a Quest, Ethical, and Strong. Beowulf is glorified not only because of his noble birth, but because of his past deeds and accomplishments. Beowulf is on a quest, no only at the beginning of the poem (to kill Grendel), but throughout the poem - his mission is to gain more fame and fortune. He is considered ethical because of his protective nature and willingness to help the Danes with their problem. Although it is debated, I would argue that Beowulf gradually loses this trait through the story. Lastly, Beowulf is strong. His strength is exemplified through his capability to complete tasks no other man can complete, such as ripping off Grendel's arm, lifting and wielding the giant-forged sword, and carrying Grendel's head without assistance.
An epic hero has to perform heroic deeds. Beowulf kills Grendel, Grendel's mother, and the dragon, all of which are heroic deeds that no one else was able or willing to take on. The foes that Beowulf fought were all beyond human strength and capabilities and required superhuman abilities to bring down. Beowulf performed these deeds for the good of others which is another quality of an epic hero. In the end, though, it was the human mortality of Beowulf which brought him down when the poison wound caused by the dragon resulted in Beowulf's death.