Basically, the copyright on the digital file (STL) that you create from scratch using your modelling/sculpting skills using well-known elements of the modern media culture for inspiration is owned by you as a 3D artist and you can legally earn money for this digital file. You can read detailed information here: https://gambody.zendesk.com/hc/en-us/articles/360020115992.
The situation with the physical items differs from the one with digital files. The thing is, the digital file (STL file) is a result of your work that you create from beginning to end, using your acquired skills either drawing inspiration from any characters or depicting your own vision of the appearance of certain heroes or objects. Besides, a digital file is a so-called settings/code that in itself doesn’t represent any model but only when engaging a third party can be turned into a physical item.
In the worldwide market, there are rules as for distribution of the physical goods. Such rules are usually created by big companies and no matter the reasons behind these rules we are obliged to follow them and as a result, some elements of physical items we create ourselves can coincide with those physical items the rules apply to. That is why, it doesn’t matter if you are a client who purchases the STL files or a 3D artist who creates them himself, all the digital files (STL files for 3D printing) can be treated only according to the Regular Permission that presupposes only personal use of the STL files available on our marketplace. Any commercial activity with the physical items created from these STL files can raise additional questions first of all regarding those who distribute these physical items. And on our part, Gambody tries to notify both our customers and authors in advance and prevent such cases in general by indicating this in marketplace’s Terms of Usage and Regular Permission.