Beowulf's tragic defect is the reason and his tragic flaw is his hubris. He was so arrogant that he overestimated himself and thought that he could beat a dragon alone. This pride drove to his release.
Explanation;
After Beowulf displays the ruler of the Geats, one day a robber invades and disorders a barrow where a dragon was resting guard to a wealth. This provokes the dragon and it begins to spit fire on the people of Geats. Beowulf continues to fight this dragon. Though he kills the dragon, the dragon bites him through their fight, the venom from which witnesses to be deadly, killing him. This is how the hero appears with a shocking end.
