Comment by AnthonyMouse

The way it's coded, if you don't specify something more specific, asking for "plumber in a red hat" implies that you're asking for Mario, because that's the most well-known instance of what you requested. If you want something else, you ask for something else. Specify the ways in which you want your plumber in a red hat to differ from the most well-known instance, and it will.

If you want the Spelunky protagonist you can literally type "spelunky protagonist" into the prompt and it will do it, or you can describe how you want your own parody to differ from the original. But if you just type "Indiana Jones" into the prompt and nothing else, you're getting Indiana Jones, because what else is it even supposed to do with that? And likewise if you use a prompt which is designed to conjure India Jones by description rather than by name.