Zim is a short little irken with a big attitude. In fact, he's so full of himself that he doesn't notice that the rest of his society hates him.
After foiling the Almighty Tallest's planned attempt a galactic conquest, Zim was banished to the planet FoodCourtia; however, he "quits" when he learns that the tallest are launching Operation Impending Doom 2. To be rid of zim, the tallest send him on a "secret mission"...to take over a little planet know as Earth...