When does Invader Zim return?

Invader Zim is an American animated science fiction horror comedy television series. It was created by comic book writer and cartoonist Jhonen Vasquez for Nickelodeon. The series centers on the titular character Zim, an extraterrestrial from the planet Irk. Zim's mission is to conquer Earth and enslave the human race along with his malfunctioning robot servant GIR. As the series went on, ratings declined and budgetary issues became more frequent. Before the second season was completed the series was cancelled, leaving several episodes unfinished. Despite cancellation and short run, it has been widely regarded as a cult classic.