Bilbo and the Dragon

“Dragons steal gold and jewels, you know, from men and elves and dwarves, wherever they can find them; and they guard their plunder for as long as they live, and never enjoy a brass ring of it. Indeed, they hardly know a good bit of work from a bad, although they usually have a good notion of the current market value; and they can’t make a thing for themselves, not even mend a little loose scale on their armour”

The Hobbit.