You may be accustomed to some loving and friendly dragons that you have seen, read or watched but there also dragons that were not so likable and must be defeated and killed.  Because of its size, power and other strong traits, many dragons played the role of a villain.  They attack people, destroy properties, hoard treasures and many more. 

In English literature, Beowulf is regarded as the oldest piece of writing.  It tells the story of a Scandinavian warrior during the sixth century.  It is a famous epic about a Geatish hero who frees the Danish kingdom of Hrothgar from 2 evil spirit monsters.  Later in the story, Beowulf accidentally discovers a dragon treasure near his town.  Enchanted by a golden goblet, he stole it.  When the dragon realized that it was gone, it made him furious and attacked the town villages. Beowulf battled with the dragon and killed it.  Unfortunately, during the clash the dragon bit him and the poison from the dragon's mouth caused Beowulf his life.

Saint George is believed to be a Roman Calvary official.  He is celebrated for his courage during war.  The town of Cappadocia was threatened by a dragon so the townsfolk fed it with sheep.  Later on, the town ran out of sheep so they began feeding maidens to the terrible dragon.  Unfortunately the time comes when the princess is the one only one left so Saint George battled with dragon until he killed it with his sword steed.  He did rescue the princess and due to this, he was able to convert the town to Christianity.