One of the most fascinating characters I've learned of since getting into PD stuff is Krazy Kat - a cartoon character from the 1910s who is explicitly and unambiguously genderfluid - not in the sense that they sometimes wear drag like Bugs Bunny, or that they occasionally play the role of another gender in a cartoons-as-actors sense, but it's explicitly discussed in the comic that Krazy is sometimes a woman and sometimes a man.