Chrysophylax
Farmer Giles of Ham
The dragon Chrysophylax appears in the tale Farmer Giles of Ham by J.R.R.Tolkien of Lord of the Rings fame. The story was first published in 1949.
Unlike most of Tolkien's work, Father Giles of Ham was not based in a fantasy world but rather in a fantasized version of past England. In some ways the world of Ham is similar to the "medieval + magic" world of many fantasy games
Giles is very much an "accidental hero". He is a simple farmer, fat and not very bright. When a giant loseshis way and wandered into Ham, Giles manages to accidentally scare him away with a blunderbuss. The villagers proclaim Giles a hero and exaggerated tales of the incident begin to spread. Eventually the King hears of Giles's feat and rewards him with a sword called Caudimordax or "Tailbiter". This was, of course, a magic sword with special powers against dragons.
The giant meanwhile had returned home. Not wanting to admit that he had been scared off by a farmer the giant pretended that there were no knights in the area just a few wasps that had stung him.
The giant's story is heard by the dragon Chrysophylax Dives who decides that with no knights left to worry him he should investigate the region.
The king and his knights want nothing to do with a risky activiy like dragon slaying - they're more interested in discussing the finer points of court etiquette. So everyone assumes that the "hero" Giles will slay the dragon with his magic sword.
A series of incidents and encounters follow which poke fun at the greed of the king and the people of Ham. Eventually, of course, it all ends happily ever after.