I just realized something: Zim is Dagget (from the Angry Beavers, a suprisingly good Nickelodeon cartoon), or at least, they have the same voice actor. I can't believe I didn't recognize this before. Surely, Zim's voice is different from Dagget's, but when I think about it's obvious... especially since that particular voice actor (whose name I cannot spell for the life of me) has a wonderful talent for degenerating into grring babble like both Zim and Dagget have a tendency to do.