Invader Zim is an American animated television series created by Jhonen Vasquez. It was produced by and subsequently aired on Nickelodeon. The series revolves around an extraterrestrial named Zim from the planet Irk, and his ongoing mission to conquer and destroy a dark and satirical version of Earth. His various attempts to subjugate and destroy the human race are invariably undermined by some combination of his own ineptitude, his malfunctioning robot servant GIR, and his arch-nemesis Dib, one of very few humans attentive enough to be aware of Zim's identity. Invader Zim was first broadcast on March 30, 2001. The show was targeted at children in their early teens, and met with critical acclaim. However, after the first season, the show's ratings began to suffer. Before the second season was completed, Nickelodeon canceled the series, leaving at least sixteen episodes and a planned television movie series finale unfinished. Because of its continued fan base and above average DVD sales since cancellation, Invader Zim has gained a cult following. The series consists of a pilot episode, forty-six canon episodes, and at least seventeen episodes that were in production at the time of the series' cancellation. As of August 19, 2006, all forty-six canon episodes have aired on television and been released on DVD. Nineteen of the episodes are split into two individual stories, each lasting about twelve minutes. There are eight double-length episodes. Almost every episode was directed by Steve Ressel; the only exception is the pilot episode, which was directed by Jordan Reichek.