I was distressed to find a grammatical error in the end credits of Harry Potter and the Prisoner of Azkaban. As part of the art surrounding the credits, the legend "The Monster Book of Monster's" was seen.
Unfortunately, "Monster's", with the apostrophe, is the possessive form, and "Monsters", without the apostrophe, is the plural form. As the title of the book refers to plural monsters, the possessive form is clearly incorrect.
Seeing an error like this in a piece of student writing is painfully frequent. While I understand that the Marauder's Map was intended to be the creation of four teenage boys, this movie is also very influential to young people. I do not consider inspiring young people to punctuate like the Marauders at all a positive influence.
I humbly suggest that the grammatical error in the illustration of the end credits be removed for future releases of the film.