Is taking Harry Potter quizzes online or watching the movies just for fun haram or shirk in any way?
Alsalam alikum brother / sister. I will not give you a direct ruling because i hav'nt watched these movies to be honest but i will give you a genreall ruling that you can apply.
If there is anything haram in the movie then watching it is haram like affectionte scenes and all that stuff and it is better to optain from watching them.
And rember brother this world is nothing but a test so if you do good now you will live later with whatever you desier inshallah.
May allah guide me and you. And Allah knows best.