Source of image from: http://www-scf.usc.edu/~jobe/class/ahis/invader_zim/
- The story is about an impulsive yet incompetent alien invader named Zim who tries to conquer the earth while staying undercover as a school boy.
- He has a dopey robot minion named GIR who wears a green dog suit in public.
- The only person at Zim's school that sees through his schemes and his disguise is a boy named Dib who is obsessed with the paranormal.
- He tries to open everyone's eyes to his knowledge but they all think he is crazy.
- In the series Zim and Dib are constantly competing with each other over the fate of mankind.
Source of image from: http://irkenarmada.info/
I am not certain why this happened, but it could be because of how dark some of the episodes were with topics too scary for young audiences.
Another reason could be that the quality of the animation became too expensive for the Nickelodeon Studios to produce on a limited budget.
Whatever the reasons, Invader ZIM formed a huge fan base and merchandise sold like hotcakes. Its first episode, The Nightmare Begins, received two awards and the whole television series became one of the highest rated cartoons in America.
In retrospect, Invader ZIM probably wouldn't have become so popular if it wasn't for it being discontinued.
Bellow are links to a pilot episode of Invader ZIM. Feel free to watch.