This is a list of characters from the animated Nickelodeon TV series Invader Zim. The recurring cast includes long-term Nickelodeon voice actors Richard Steven Horvitz and Rodger Bumpass, as well as actors from live-action television such as Kevin McDonald (Kids in the Hall) and John de Lancie (Star Trek: The Next Generation). The creator and writer of Invader Zim, Jhonen Vasquez, also voices parts in the show.
Overzealous, impulsive, and convinced of his own greatness, Zim is incompetent as an invader. He dreams of pleasing his species' leaders the Almighty Tallest, by taking part in Operation Impending Doom II, which is an Irken military initiative to conquer the universe. The Tallest send him to Earth (a planet of no interest to the Empire on the outskirts of the known universe) on a fake mission of conquest. They were expecting him to die or become lost on route. Against the odds, Zim lands on Earth, establishes a base and, much to the chagrin of the Tallest, routine communication with his home world. Because of his stature, Zim disguises himself as a human child using a wig to cover his antennae and lenses to make his eyes look normal. Despite his tendency to vociferously malign humans as a species, his undisguised green skin, a severe allergy to water, his refusal to eat human food, multiple failures in his disguise, and an occasionally blatant disregard for his own cover, no one realizes that Zim is an alien—with the exception of Dib. In spite of his slight build, Zim occasionally displays superhuman strength and agility, although due to the show's lack of continuity, these traits are not always present. He is never without his PAK, a backpack-like piece of equipment with long, retractable arms that enable him to move about quickly and climb almost any obstacle. Zim constantly schemes to enslave or destroy mankind, and despite his access to potent Irken technology, his plans, frequently based on misconceptions, are never successful. He serves as the main protagonist of the series but he is the one who wanted to destroy earth and because of that, Zim serves as the main antagonist from time to time.
Zim's only companion, GIR, is a SIR (Standard Information Retrieval) unit, an Irken standard-issue robot. He is completely made of different parts from SIR units found in a trash can. The name "GIR" is a self-applied moniker that is never explained, GIR himself states that he doesn't know why he refers to himself as GIR, ("GIR, reporting for duty." Zim: "'GIR?' What does the G stand for?" GIR: "I don't know!") but it is insinuated in the show the G stands for garbage. GIR differs physically from other SIR units in that his head contains odds-and-ends rather than artificial intelligence hardware. Because of this GIR displays a wildly erratic personality. He is almost completely irreverent, and rarely obeys Zim's commands, variously due to distraction, disinterest and disobedience, but when he does, his eyes glow red like normal SIR's and he will usually refer to Zim as "My Lord" or sometimes "My Master", but in the episode, "Gir Goes Crazy and Stuff," Zim actually tries to improve Gir's obedience skills but it ends up backfiring when Gir sees him as an enemy. GIR disguises himself by wearing a green dog suit which fools most humans, despite looking and acting almost nothing like an Earth dog. He also does things that a real dog wouldn't do, such as talking in public, dancing and using jet rockets.
He is Zim's mortal enemy and is highly unpopular at school (where he shares a class with Zim) and at home for his broken record obsession with the paranormal, aliens, Bigfoot, the Loch Ness Monster, and other paranormal phenomena. He and his sister, Gaz (Who couldn't care less.), are some of the only humans who know that Zim is actually an alien. He is the co-protagonist of the series, but at the same time being the antagonist because he is constantly trying to break into Zim's house, or even go as far as pushing Zim into water (which is equivalent to acid to Zim's skin). Dib tries constantly to convince his classmates that Zim is an alien, but they do not believe him because he has cried wolf so many times before. Dib is so unpopular that the children will not accept his help for anything (even if the situation life threatening) because it would mean having to interact with him. His constant harassment of Zim is sometimes seen as an act of bullying by others, but this does not necessarily mean that Zim himself is popular either. Dib is part of a society of Paranormal investigators called 'The Swollen Eyeball' where his code name is Agent Mothman. In the episode, "Zim Eats Waffles",he tries to show them proof after he successfully planted a camera in Zim's kitchen. Though, because of broken software he is not able to record his sightings. There are many times were the other agents could have seen what was going on, but because of their bad timing they answered his call when things had already calmed down.
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Official Site: Nickelodeon
Links: Wikipedia Invader Zim.TV: Ms. Bitters IMDB: Invader Zim