sentences:  A pilot for "Invader Zim" was pitched to Nickelodeon in 1999, which led to the series being green-lit.Vasquez indicated that very little of his writing style was changed over the course of "Invader Zim", other than restricting certain language and visuals that may not be suitable for children.Vasquez cited that the biggest change for himself was going from working alone on a comic to working with thousands of people at Nickelodeon, saying "it's an absolute misery".