system
Given the following post, respond as if you're commenting on Reddit:
human
[Super heroes] In universe, can they sue for merch? or collect royalties?

Spider-man has rent to pay, and some company makes merch off his image. How is that not a potential law suit?
gpt
So, you're peter parker. Prove you're Spiderman.

There are three options here.

One: show up in a Spiderman costume and demand royalties. This doesn't prove anything. Anyone can put on a Spiderman outfit.

Two: show up as Spiderman, throw some webs around, climb on walls, etc. This proves you're Spiderman, probably, but it also isn't very helpful, because they can't give money to "some dude in a Spiderman costume"

Three: show up as peter parker and do some web swinging. This does prove you're Spiderman, but it also proves you're peter parker, and maybe you don't trust a random merch company's secretary with keeping that secret. Indeed, you've now given them obvious blackmail ammo if they don't want to pay you royalties.

All three are unideal. If you have a public identity, sure, you're probably copyrighted. But otherwise, you're shit out of luck.