There are many different Harry Potter trivia puzzles that can be found online, some better than others. Did JKR ever create any herself?
Fiendishly Difficult Crossword
Appeared in the forth and final issue of The Daily Prophet.
Sadly this is not available outside of private collections. A glimpse of the contents can be found on the Harry Potter Lexicon and in J.K. Rowling - A Bibliography.
W.O.M.B.A.T. (Wizards’ Ordinary Magic and Basic Aptitude test)
They were three of these (Grade 1 through 3). They were released on JK Rowling's old website for limited times starting on March 31st, 2006. Back when they were online, it was possible to get a grade on them, although the answers were never officially released.
The questions (along with commentary by Steve Vander Ark and Belinda Hobbs) can be found archived on the Harry Potter Lexicon. Fortunately, a fan back then by the name of Roonwit had systematically taken them multiple times to determine what all of the correct answers were.
- JK Rowling also wrote three personality quizzes for Pottermore: a Sorting Hat quiz, a wand quiz, and a Patronus quiz (which was never released).
- Scholastic and Bloomsbury have both made online Harry Potter trivia challenges.
- Trivia board games were released by Mattel based on the first and second books.