Defenestration posted:

When you start talking about Darth Vader, Mickey Mouse, etc. you're into the area of licensed characters. When you sub-license a character out, that means you sell the rights to use that character's image to a toy company, a lunchbox company, etc. As you can imagine, depending on the character, this is very profitable. If someone produces an unlicensed product to bank on a Disney character's popularity, that's a serious threat to Disney's profits (and potentially their brand, if you're making unlicensed Little Mermaid dildos or whatever)

Thus, companies like Disney and Lucasfilm have their characters copyrighted, and on a pretty severe lockdown. If they see that you are profiting from a mustache parody of Mickey Mouse, they will definitely sue your rear end. Depending on how much money you have to lawyer up (lol), and whether the court decides that your version is covered under fair use (heavily dependent on how similar your character is to the original and the intent of your version--to critique Disney, or to make profit?) then you MIGHT win.

Mickey Mouse and Darth Vader are still under copyright (see: The Mickey Mouse curve), whereas Mona Lisa is not. Photographs others have taken of the Mona Lisa ARE still copyrighted to the owner though, so it's not just that any picture of the Mona Lisa is public domain.

You can get away with a lot more, fair use wise, if you're not profiting