ZIM

"VICTORY! VICTORY FOR ZIM!"

- Zim, when he seemingly wins

"Fool! Do you wish to incur the wrath of ZIM?!?"

- Zim

"NOOOOOOOOOOOOOOOO!!!"

- Zim, when his missions fail

Invader Zim is the titular protagonist of the show of the same name. He is a Planet Irk agent and GIR's master and best friend who wants to take over Earth in order to get respect from his superiors. Because of this behavior, Zim is often thought to be the true antagonist.

Beginnings
Zim is an alien from Planet Irk who wasn't well-respected because of his small size. He lost all trust from his fellow invaders when he botched an invasion mission, and he ended up destroying a part of Irk. Hoping to get rid of him, Invader Zim's superiors the Almighty Tallest sent him away with a defected robot that dubbed itself GIR to a secluded area of space on a fake invasion mission, hoping that he would never find his way back. Unfortunately, Zim found Earth and he thought that it was his mission to conquer it.

In Invader Zim
Throughout the show, Zim tries many roundabout ways of taking over Earth. But he has to wear a human costume with contacts and a wig, which all but his enemy, Dib, fall for. Unfortunately for Dib, nobody ever believes him when he tells them that Zim's really an alien; Zim even said in one episode that he had a "skin condition", and when Dib suspiciously asks if having no ears is part of his "condition", to which Zim (who was pretending to be sad) replied, "Yes..." The show follows his (and sometimes Dib) odd antics, from stuffing himself with human organs to avoid being revealed to the school nurse or getting a job at a fast food company.

Zim wants nothing more than to take over Earth and impress his superiors. It was originally intended that he take over Earth and become the Tallest, but the show was cancelled before that could happen. Jhonen Vasquez stated that Zim (and the 3 other main characters) aren't factually evil.

Personality
Zim is an intense megalomaniac and he often speaks in the 3rd person. He hates humans and all things related to them. He is so smart that he can build things, but dumb in the fact that, well everything else.

He has a short and violet temper, especially with GIR whenever he annoys him.

Trivia

 * Despite that he wasn't proved to be a truly evil character at first, he crossed the Moral Event Horizon when upon killing Dib slowly and over many years using time-travel technology, he calls him a "foolish Earth creature" and walks away while drinking a soda. Dib is revived almost immediately, but Zim wasn't aware of this at the time.
 * Because of his diabolical plans, Zim is usually confused to be the main villain.
 * One of the working plot ideas for the series finale Invader Dib would have had Zim defeating Dib and Tak and becoming Almighty Tallest soon thereafter, deposing Tallest Red and Purple from the throne; knowing that he must have a queen to rule he would have chosen Gaz, with whom he had teamed up with after she (cloaked in a hood to hide her identity until the time is right, with only her amber eyes visible in the shadows) encouraged him to fight on to save his people from certain death. Additionally, he would begin to lose his desire to conquer Earth and, as Jhonen claims, see the beauty in Earth life and thus completely lose his desire to destroy the planet.