StoryAfter Beowulf had rid Denmark of Grendel, and his Mother, Beowulf became king of the Geats and ruled for 20 years after. He eventually had to face the dragon when it awakened, who began destroying villages after a slave stole a golden cup to buy his freedom. This enraged the dragon, who proceeded to ravage the countryside and destroy any and all in its path.
Beowulf soon went to challenge the dragon in its territory, where both fought valiantly. During the battle, all Beowulf's men fled, save for his most trusted and loyal warrior, Wiglaf, who stayed by his king's side to fight. Beowulf soon received fatal blow in the neck from the dragon's venomous bite, but Wiglaf impaled the dragon's belly to reduce the flames, and Beowulf deals the fatal blow. In his death-speech, Beowulf nominates Wiglaf as his heir, and that of the treasure. The Dragon, its body some 25 alens (50 feet) long, is tossed unceremoniously into the sea.
The dragon appears in the 2007 film, but is in this depiction a golden dragon that is the protagonist's son, the result of an affair between Beowulf and Grendel's mother. One day, a slave named Cain belonging to Beowulf's servant, Unferth finds the golden drinking horn Beowulf left Grendel's mother as placation in a swamp near Grendel's cave and brings it back to the kingdom. That night, a nearby village is destroyed by the dragon, which leaves Unferth alive to deliver a message to King Beowulf: the dragon is Beowulf's son born to Grendel's mother. Removing the horn has voided the agreement between Beowulf and Grendel's mother, who has now sent their son, the dragon, to destroy his kingdom.
Beowulf and Wiglaf go to the cave once again and Beowulf enters the cave alone. When Grendel's mother appears, Beowulf gives her the golden horn, but she refuses to stop the attacks and the dragon emerges. The dragon flies straight towards Beowulf's home, threatening his wife Wealtheow and his mistress, Ursula. Despite his age, Beowulf goes to great lengths to stop the monster, even slicing off his own arm in an attempt to reach its only weak spot. Eventually, he kills the dragon by ripping its heart out, and they fall into the sea below the castle. A mortally wounded Beowulf lies on the beach and watches the dragon transforming into the humanoid body of his son and it washing out to sea. As Wiglaf approaches him, Beowulf tries to tell the truth about his affair with Grendel's mother, but Wiglaf insists on keeping his legacy intact. Beowulf dies shortly after.