The movie that comes to mind for me is Matango. It’s a 1963 Japanese horror film by Ishirô Honda (the director of the Godzilla movies) that IMDb describes as “Shipwrecked survivors slowly transform into mushrooms.”.
I was curious what other PG horror movies people like. I find a lot of the time the limitations or target of an age rating can become noticeable and distracting.
I think that’s a fantastic description for Willy Wonka. I remember as a kid watching the boat ride scene and thinking “is Mom sure this is a kid’s movie‽”