This is a fifteenth-century roof boss in the cloisters at Lacock Abbey. By the looks of it the dragon is singing as well as playing a seven-string harp. What songs do dragons sing? Fierce, wild songs, I imagine. There are sharp teeth in those jaws. This is not a tame creature.
The carvings at Lacock include two mermaids, a manticore, Reynard the Fox making off with a goose, and a bowman who is possibly meant for Robin Hood. I have put all my photos of the Lacock roof bosses in a Flickr set.