I am not an attorney and any comments I post are not intended, nor should they be construed, as legal advice. If you need legal advice, please consult a legal expert who is familiar with the area of legal expertise you need.
This post is a result of this post – https://pictinpa.wordpress.com/2019/11/07/jaws/ and the memory jogged by her drawing.
I have not seen Jaws the original movie with the exception of bits and pieces over the years. I read the book and did a book report on it in one of my English classes. Our teacher required we don’t reveal the end of the book as an incentive to encourage other students to read the book. At the end of my report, there was a Q&A where classmates could ask questions or clarifications that didn’t involve how the book ended. One of my classmates had seen the movie, but not read the book. The question involved the ending of the movie. I answered by saying that’s not what happened in the book without going into details on how the book ended.
If you ever plan on becoming an author, or you simply stumble into becoming one, be aware there are differences between the books and the movies. For example, a point made by this blogger 3 Ways Copyright Shaped Halloween — Plagiarism Today; original post https://www.plagiarismtoday.com/2019/10/31/3-ways-copyright-shaped-halloween/ (see also https://www.plagiarismtoday.com/2011/10/24/how-universal-re-copyrighted-frankensteins-monster/) – specifically point #3 shows how Frankenstein is under public domain for the books written by Mary Shelley, but not for the movies that were made later by movie studios that included aspects not covered in her books. Jf you stick with referencing Frankenstein’s monster without going into details about his appearance, you should be safe. Where you run into problems is talking about his appearance or things that were added, changed, or clarified in any of the movies made by Universal Studios or other studios.
The same holds true for any other book that was made into a movie, TV series, etc. where the original book is in the public domain, but added new or different things that weren’t in the public domain books. A great example is most of the Sherlock Holmes books are in the public domain although a handful remain under copyright – Sherlock Holmes and Copyright. Any movies or books made about the detective that include things that are still under copyright or are new things added by a studio or later author would be something to be avoided.