The 5000 Fingers of Dr. T
Buckle your seatbelts! This is a weird one. The 5000 Fingers of Dr. T is a 1953 movie musical writen by Theodor Seuss Geisel, better known as Dr. Seuss. It's also the colossal flop that made him scared to return to the film industry for decades.
There is so much to love about this movie. The classic dream sequence of a kid who falls asleep during piano lessons and dreams of his teacher as a facist dictator forcing all little boys to learn piano. The 50's golden age score. The absurd dialogue. And of course the visuals, the visuals, the VISUALS!!!
Thank the gods for the internet archive, you can watch it right now! I wouldn't be too concerend about spoilers though, the story is pretty simple.
I'm also almost positive this movie inspired that one Goosebumps book/episode.