There are lots of creators out there who like to appropriate images in order to create fun and engaging items on the grid. The problem is, how do you do this without getting zapped with a DMCA notice, or just plain coming off as an asshole?
The answer is to refer to films, cartoons, and other similar work that is in the public domain or is royalty free.
Here is a small list to refer to for films you can use in your creations. As always with Wikipedia, do some research on your own to make sure the creative work listed is actually free to use, just in case.
I’m sure there’s more out there, but this list will help get some people started. Please remember to do additional research to make sure your creations are in the clear.