Invader Zim is an American animated science fiction dark comedy television series created by comic book writer and cartoonist Jhonen Vasquez for Nickelodeon.

[16][18] Invader Zim received positive reviews from critics and audiences,[16] with praise primarily directed at its humor, writing, animation, art-style, and the way it pushed the boundaries of what was considered acceptable on children's television.

Zim successfully pleads to be made an Invader, and receives a "secret mission" intended to prevent interference with the invasion; the target "mystery planet" is on the outskirts of the known universe and is not confirmed to exist.

After a six-month journey across the universe, Zim arrives at the "mystery planet" which turns out to be a dark, dystopian, and satirical version of Earth centuries into the future, with rampant mindless consumerism, although it appears that humans have abolished all wars.

[36][37] Nickelodeon producer Mary Harrington was searching for something that had a similar "edge" to The Ren & Stimpy Show, when she came across a comic book called Johnny the Homicidal Maniac and was impressed with the art-style and character designs in the series.

[57] Additionally, the episode "Hamstergeddon" had only aired once prior to the attacks on the World Trade Center, and would shortly thereafter be temporarily withheld from rotation as "[executives] thought the sight of falling buildings would not go over well with sensitive viewers.

[46] Also, at the end of "Bestest Friend", Keef was originally going to fall off of a building and onto a power line, which would have electrocuted him, but Nickelodeon was worried that kids might try to imitate this behavior and demanded that it be changed.

[35]Invader Zim was too dark and subversive for Nick's core demographic — and much of the humor flew past the heads of their younger viewers — but in retrospect Vasquez and his director Steve Ressel did everything right.

— Jerry Beck, Animation Historian[71] When Invader Zim was green-lit, Nickelodeon had desired a block of "mature, action-oriented" programming for an older demographic to compete with what Cartoon Network was doing at the time.

[40][78][56][35][55] Invader Zim suffered creatively after 9/11 and Nickelodeon began frequently and inconveniently changing the shows' time slots with little promotion for new episodes which led to an even further drop in ratings and viewership.

Screen Rant's Spencer Coriaty wrote: "Backed by some of the most cutting edge animation at the time, and still breathtaking by today's standards, Invader Zim is like a Mystery Science Theater fan's dream come true.

While jokes could easily revolve around the high-pitched screams of Zim's useless robot companion, GIR, the comedy was also often derived from much darker places, like harvesting organs from living children and lice outbreaks and characters slowly turning into a sentient [bologna].

"[22] Alex Bedder, from NYU Local, said, "Essentially the black sheep of the animated Nickelodeon family, Invader Zim never quite stuck its landing, but it became a beloved and off-kilter fan favorite.

Vasquez and co-writer Rob Hummel throw in some clever quips at life on this planet, taking aim particularly at the doomsaying schoolteacher, Ms. Bitters [and] Kevin Manthei's music provides strong accompaniment to the escapades.

"[95] Sean Fitz-Gerald from Thrillist wrote: "Though Invader Zim came from Jhonen Vasquez, the same beautifully twisted mind behind Johnny the Homicidal Maniac, the [show] manages to hold off on graphic violence and obscenities without losing all its bite.

"[96] Joe Matar writing for Den of Geek wrote: "Invader Zim is a brilliant piece of unsettling, grotesque horror, with a heart of goofiness, which is a big part of its appeal.

"[99] Lynne Heffley, writing for Los Angeles Times said "The deliriously original Invader Zim rocks" offering praise for the show's humor and art-style, calling it a "visual feast of geometric lines, strange angles, vaulting curves, fantastic, transforming machines and odd, shadowed places.

The website's critical consensus for season one reads: "The right balance of dark humor and spastic earnestness make Invader Zim a creepy kid's cartoon worthy of its cult following.

[102] Common Sense Media's Andrea Graham wrote more negatively of Invader Zim, praising the show's "laugh-out-loud" humor, but criticizing the way that Zim has a complete lack of concern for all life, how humans are depicted as less-than-intelligent life forms, how human society is depicted as a terrible disgusting place, the very frequent use of verbal insults, and that there is no good messages or good role models in the show.

[125]) Special guests included cast members Richard Steven Horvitz, Melissa Fahn, Rosearik Rikki Simons, Andy Berman and writer Eric Trueheart.

[122] Special guests included cast members Richard Steven Horvitz, Melissa Fahn, Rosearik Rikki Simons, Rodger Bumpass and writer Eric Trueheart.

It featured Richard Horvitz, Rikki Simons, Rodger Bumpass, Melissa Fahn, Olivia d’Abo, Wally Wingert, Aaron Alexovich, Eric Trueheart and Kevin Manthei.

[162][163] In 2018, Wally Wingert, the voice of Almighty Tallest Red, noted during an interview with Den of Geek that "[T]he reason other shows like Adventure Time are [able to do some pretty intense stuff] is because the trail was blazed by [Jhonen Vasquez].

"[165] That same year, Eric Vilas-Boas from Thrillist wrote "[Invader Zim] remained an influential cult classic, informing future cartoons like Avatar: The Last Airbender all the way up to Steven Universe, Gravity Falls, Rick and Morty, and beyond.

[195] Zim, alongside Rocko, Danny Phantom, Jenny XJ9, and Powdered Toast Man, were released as playable skins for a limited-time Nickelodeon-themed event in Smite on July 12, 2022.

The book collects more than five hundred illustrations, images, storyboards, concept art, quotes, interviews and anecdotes, among other special behind-the-scenes content for Nickelodeon's first thirty-one cartoons.

"[207] Zim and GIR flying in the Voot Cruiser made a cameo appearance in the now-defunct simulator ride Jimmy Neutron's Nicktoon Blast at Universal Studios Florida.

[208][209] In the 2013 animated feature film Escape from Planet Earth, the word "Zim" can be seen written on the floor in graffiti in one brief scene, along with the names of multiple other aliens from various different movies and television shows.

[242] a separate set of smaller non-articulated figurines, featuring: Zim in his human disguise first seen in "The Girl Who Cried Gnome", Gaz in her Beaver Suit, Bologna Dib and GIR riding the Piggy.

This set contains figurines of: Screaming Zim in his human disguise, Doggie Suit Duty Mode GIR, Neutral Faced Almighty Tallest Red, Hypnotized Dib, and Shadow Ms.