Is this sense of "masterpiece" well known? Can I use it in a piece for undergraduates without having to stop and explain it?
In another part of the forest... it's well known that J. K. Rowling uses various creatures from folklore and myth, etc. Mostly, she uses them fairly "straight" - a werewolf in the Potterverse is much like a werewolf in most other places one encounters them, and is subject to the same rules. So why does she play such silly buggers with the good old boggart? This mischievous household spirit of the genus Poltergeist is hardly the most obscure - but when a boggart makes an appearance in The Prisoner of Azkaban it's quite different from its traditional manifestation, being described as "a shape-shifter [that...] can take the shape of whatever it thinks will frighten us most". No one knows what Rowling's boggart looks like when it is unobserved, making it some kind of cross between Schrödinger's cat and Room 101 - in fact, nothing like a boggart at all except in its desire to mischief humans. Yet now, to my students (and no doubt to their contemporaries the world over) that is what a boggart is. I find that regrettable - but also out of character for Rowling, who tends to play things fairly straight.