Invader Zim may have forged an enduring legacy, but the series still ended after just two seasons. Created by cartoonist Jhonen Vasquez for Nickelodeon, the animated dark comedy unapologetically pushed the boundaries of children's television with morbid, counterculture humor and the grisly nature of its overarching storyline. Invader Zim followed the titular alien as he attempted to conquer Earth and enslave the human race under the order of the Irken Empire — a mission he repeatedly failed at to hilarious effect.
https://screenrant.com/why-invader-zim-ended-season-2-canceled/