Invader Zim characters include Zim, GIR, Dib, Gaz, Miss Bitters, Professor Membrane, the Almighty Tallest, Tak, and a deep bench of skool kids and Irken misfits who appear for thirty seconds and stay with you for decades.
The show only ran for a season and a half before Nickelodeon pulled it, so the roster of Invader Zim characters is small.
That has never stopped anyone arguing about it.
Below I have ranked the Invader Zim characters worth ranking, from the ones who exist to fill a corridor to the one who ended up on more merchandise than the title character.
I have ranked these Invader Zim characters by how much they matter: how memorable they are, how much they add to the show, and how well they have survived twenty-odd years of the internet.
Best Invader Zim Characters, Ranked
Before the list of Invader Zim characters, credit where it is due. The visual style is half of why these characters stick. Bold colours, warped perspective, and the grimy-futuristic mix give even the background kids a design you remember. Zim’s house is a suburban home with a monstrous secret underneath it, which is the whole series in one image.
Torque Smacky
Every skool needs a bully, and Torque Smacky fills the slot without ever becoming interesting enough to be scary. He is muscle in a show where muscle counts for nothing.
- Role: Skool bully and background muscle
- Best used in: Crowd scenes and the odd Zim scheme
- Trait: Large, loud, easily manipulated
Iggins
Iggins is the kid who snatches the last Game Slave 2 out from under Gaz in a shop queue. That is his entire crime, and the show treats it as a capital offence.
- Role: Gaz’s video game rival
- Voiced by: Paul Greenberg
- Best episode: Game Slave 2
Zita
Zita is one of the few classmates with a name and a recurring face, usually rolling her eyes at whatever Dib is shouting about. She is the audience surrogate for everyone who has decided Dib is exhausting.
- Role: Skool classmate and professional sceptic
- Voiced by: Mo Collins
- Trait: Dismisses Dib no matter how much evidence he produces
Bloaty and Sizz-Lorr
Two characters people constantly lump together, and they have nothing to do with each other. Bloaty is the mascot of an Earth pizza chain. Sizz-Lorr is the enormous Irken frycook who once had Zim as an employee.
- Bloaty: Mascot of Bloaty’s Pizza Hog, a restaurant on Earth
- Sizz-Lorr: Zim’s boss on Foodcourtia, voiced by Jim Wise
- Best episode: The Frycook What Came from All That Space
Agent Darkbootie
Darkbootie is Dib’s contact at the Swollen Eyeball Network, a paranormal investigation group that takes itself extremely seriously and achieves nothing whatsoever. He speaks entirely in portentous whispers.
- Role: Swollen Eyeball Network agent and Dib’s only ally
- Trait: Cryptic, self-important, useless
- Function: Proof that Dib’s wider community is no better than he is
Keef
Keef decides Zim is his best friend and refuses to be talked out of it, which in this show is a horror premise rather than a sweet one. His relentless cheerfulness makes him the most disturbing child in the cast.
- Role: Zim’s self-appointed best friend
- Voiced by: Danny Cooksey
- Best episode: Bestest Friend
The Resisty
An intergalactic resistance movement opposing the Irken Empire, hampered by the fact that they are useless and cannot even agree on a decent name. Lard Nar, a Vortian, leads them.
- Leader: Lard Nar, voiced by Fred Tatasciore
- Members include: Shloonktapooxis and Spleenk
- Trait: Passionate, disorganised, permanently outgunned
The SIR Units
SIR stands for Standard-Issue Information Retrieval, and the units get assigned to Irken Invaders as servants and weapons. They are lethal, obedient, and, in every case except one, completely competent.
- Role: Irken Invader support robots
- Notable units: GIR and Tak’s unit MiMi
- Trait: Armed, jet-boosted, and mouthless
Invader Skoodge
Skoodge is the only Irken in the series who completes his mission, conquering his assigned planet properly. The Empire responds by ignoring him entirely, because he is short.
- Role: The one Irken Invader who succeeds
- Trait: Competent, loyal, and short
- Fate: Overlooked, then dumped on Zim as a houseguest
Minimoose
Minimoose turns up with no explanation, floats, squeaks, and is immediately accepted by everyone as a normal part of the world. He is also apparently capable of enormous destruction.
- Role: Zim’s second sidekick
- Trait: Floats, squeaks, never explained
- Introduced: Late in the series, with zero setup
Tak
Tak is what Zim thinks he is: focused, intelligent, and dangerously good at the job. She holds a grudge against Zim for ruining her Invader exam, and she comes very close to winning.
- Role: Rival Irken Invader
- Voiced by: Olivia d’Abo
- Best episode: Tak: The Hideous New Girl
Professor Membrane
The most famous scientist on Earth, host of Probing the Membrane of Science, and a father who communicates with his children mainly through pre-recorded messages. He has never once looked directly at the alien situation in his own house.
- Role: Dib and Gaz’s father, celebrity scientist
- Voiced by: Rodger Bumpass
- Trait: Believes in science, refuses to believe in anything else
The Almighty Tallest
Red and Purple run the Irken Empire because they are the tallest Irkens alive. That is the entire qualification. They spend most of their screen time eating snacks and trying to get off the phone with Zim.
- Role: Co-rulers of the Irken Empire
- Voiced by: Wally Wingert (Red) and Kevin McDonald (Purple)
- Trait: Bored, petty, permanently snacking
Miss Bitters
Zim and Dib’s teacher, drawn as something between a woman and a snake, who opens lessons by explaining that the children have no future. She may or may not be human and the show never clarifies.
- Role: Skool teacher
- Voiced by: Lucille Bliss
- Trait: Hisses, looms, radiates doom
Gaz
Dib’s younger sister wants to play her Game Slave and be left alone. Threaten either of those and she will dismantle your life with a patience that suggests she has done it before.
- Role: Dib’s sister, apex predator of the skool
- Voiced by: Melissa Fahn
- Best episodes: Game Slave 2 and Bloaty’s Pizza Hog
Dib
Dib is right about everything and nobody cares. He identifies the alien immediately, gathers evidence constantly, and gets treated as the strange one by a world that cannot see what is standing in front of it.
- Role: Paranormal investigator and Zim’s nemesis
- Voiced by: Andy Berman
- Trait: Correct, obsessive, comprehensively ignored
Zim
An Irken invader sent to conquer Earth by superiors who wanted him as far away as possible. He is loud, vain, relentlessly confident, and wrong about nearly everything, including the fact that his disguise is a wig and contact lenses.
- Role: Irken invader, title character
- Voiced by: Richard Steven Horvitz
- Trait: Total confidence, zero competence
GIR
Zim’s assistant, built from spare parts and scrap, and the reason the show broke containment. GIR ignores orders, eats anything, wears a green dog suit, and loves tacos with an intensity that borders on religious.
- Role: Zim’s defective SIR unit
- Voiced by: Rosearik Rikki Simons
- Trait: Chaos, with an occasional switch to a functioning duty mode
The Satire Underneath the Slime
Under the screaming and the exploding organs, the Invader Zim characters serve a comedy about conformity. Nobody notices the alien. Not because he hides well, but because noticing would require paying attention, and the humans in this show are constitutionally incapable of it.
The Irken half runs the same joke from the other direction.
An empire that promotes people by height, ignores its only competent invader for being short, and hands its most incompetent one a planet to keep him busy.
Both halves say the same thing: the systems people live inside are arbitrary, and almost nobody checks.
Why Nickelodeon Cancelled Invader Zim
Nickelodeon commissioned the show wanting something for an older audience, then found out what that meant in practice.
Episodes like “Dark Harvest,” in which Zim harvests his classmates’ organs to pad out his disguise, sat awkwardly on a network selling to children.
The cancellation itself was less dramatic than the legend suggests.
Ratings slid, the budget became a problem, and Nickelodeon pulled the plug before the second season finished.
Several completed episodes went unaired for years, and a planned feature-length finale never got made.
Unproduced scripts have leaked into fan knowledge since. “The Trial” would have put Zim in front of the Irken authorities and exposed his past, and “Ten Minutes to Doom” hinged on Zim’s PAK being removed, giving him ten minutes to live while Gaz raced to retrieve it.
Some of that material eventually surfaced in comic form.
Invader Zim After the Cancellation
This is the part most Invader Zim characters guides skip. Invader Zim did not stop in 2006.
Oni Press launched an ongoing comic starring the Invader Zim characters in 2015 with Vasquez involved, which ran for years and adapted some of the material the show never got to make. Then in 2019 Netflix released Invader Zim: Enter the Florpus, a feature-length film that brought back the original cast, including Richard Steven Horvitz, Rosearik Rikki Simons, Andy Berman, and Melissa Fahn.
For a show cancelled mid-season, getting a proper ending thirteen years later is a remarkable outcome, and it happened because the audience refused to let it go.
Why Invader Zim Still Has a Cult Following
Twenty-five years on, the fanbase around these Invader Zim characters has not thinned out. Part of that is timing: Invader Zim arrived just as internet fandom was learning what it could do, and a show this quotable and this easy to draw was perfect fuel.
The bigger part is that it never talked down to anyone. It was ugly on purpose, mean on purpose, and funny in a way that assumed you would keep up.
Plenty of cartoons have been weird since.
Very few have been this committed to it.
That is my ranking of the Invader Zim characters.
GIR at the top will annoy the people who think the title character should win by default, and Gaz at four will annoy everyone else.
If you want more chaotic cartoon robots or shows with a similarly dark streak, there is plenty more here.
So who did I rank too low?
Let me know in the comments.