Phenakistoscope
I've been testing with digital phenakistoscopes. They really are so interesting. For example, this a 12 cell disc played at 1 frame per cell (so 2 rotations per second at 24fps) 12 drawings appear static. If you have less than 12 drawings they appear to jump forward and the opposite is true if you have more than 12.. I think :)
I've linked a very thorough article by Elliot Schultz, who explains how these things work far better than I ever could here:
www.medium.com/@elliotschultz/making-of-animal-collective-s-animated-slipmat-ac3acb104863