Last night, I decided on a whim to look up Japanese clips of Invader Zim to see what pronoun Zim uses in Japanese. (I couldn't find any clips, so I never found out.) Immediately after doing so, I wondered to myself, "What gendered pronouns would Zim use in English?" This in turn led to the question: Would Zim even know what pronouns are? The answer: no, he wouldn't - in fact, he would almost certainly misconstrue them as some kind of physical phenomenon - but he would feel compelled to pretend he understands them so as to better blend in with the humans. "Like any other normal human Earth child, my pronouns are alive and numerous. They're just, uh, sleeping! At home!" - something like that.
@arcadeidea has provided me a link to a Japanese dub of an Invader Zim episode, and so we can confirm that Japanese Zim uses 俺 (ore).
