Nickelodeon contacted Jhonen Vasquez about pitching ideas for an animated series for their older demographic and Invader Zim was the first thing he pitched. In Vasquez's words "it went from pitch to series without hardly any waiting". As the series went on, ratings declined and budgetary issues became more frequent. Before the second season was completed, Nickelodeon cancelled the series, leaving several episodes unfinished. The show first ran on Nick from 2001 to 2002, with a handful of completed second-season episodes initially going unaired; these episodes were later seen on DVD in 2004 and aired on the Nicktoons Network in 2006.
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