True, Ninja coins, spiderman coins, one coin even has a Holywood country by itself and face of Eddie Murphy on it see
https://en.numista.com/catalogue/pieces49264.html these all exist on the site. They are usually uploaded to "tokens" section to which the above coin/or object could be added. The name "tokens" on this site seems to imply all sorts of exonumia, starting from horrible plastic objects, going with grotesque and kitsch and ending with marvelous artistic medals...
The tokens area of course now is a mixture of everything and very hard to use, for that reason the following topic has been created by Neilithic and actively discussed by myself and others:
"How do you think exonumia should be handled on this site?"
https://en.numista.com/forum/topic24853.html
Please do comment and present your opinions there because although none of us are actively involved in site management, as very active users, we are trying to do our best to help the Numista team and our opinions may help them design or transform tokens area better.
I myself is a firm believer that everything coin or coin-like should be represented at this site, and any numismatic object could be lovely although looking horrible at first; others may support that this site should remain only for regular, official coins and "ugly" tokens have no place here.
I wonder what we have done with my son's Star Wars token? That is surely not represented at the site and I should add it. And I really enjoyed seeing Ninja turtle coin

2000 years later no one will know about Teenage Ninja Turtles and that coin will be extremely rare, will definitely be exhibited in a museum
Surely this following was no official coin in Roman times, but now gets to be exhibited in a museum.