Which cartoons are copyright free?

I'm curious to know, which cartoons can be considered as copyright free? Are there any specific guidelines or criteria that need to be met in order for a cartoon to fall under this category? Is it possible to find a comprehensive list of copyright-free cartoons that are available for public use? Additionally, what are the potential risks or legal implications of using a cartoon that is not copyright free? It would be great if you could provide some clarity on these matters.