Gregory's Server
This is pretty cool. A list of popular characters from books, movies, animation, comics, and more, showing when their copyright expires.
https://commons.wikimedia.org/wiki/Commons:Character_copyrights
Coming up in 2026: Nancy Drew, The Three Stooges, and Betty Boop.
A very nice find via https://retro.social/@ajroach42/113770861106010609