The Dragon

At the last years of Beowulf, a desperate slave trying to buy his freedom by stealing a cup from a sleeping Dragons cave. By doing so awoken the fiery beast into destroying a nearby village to exact it's revenge on the one who stole it.

When Beowulf discovers this predicament he decides to challenge the relic of the dinosaurs to a final duel to the death. In which the dragon accepts, as the battle had been near the end the dragon bites Beowulf with a burning chemical (which was considered venom) and both died from the mortal wounds that they inflicted on each other.

Dragon's features
In the 2007 film, the Dragon is based on the Wyvern which would later be popular design for The Hobbit (2012-2014), Game of Thrones, and was inspired by Lord Maliss from Happily Ever After (because it was Beowulf's son in the film). Added with Gold elements, Beowulf's features, and even added the flying squirrel elements for the flight mechanics. Like the original had the fire breathe elements and accepted Beowulf's challenge.