Attention Deficit... Ooh, Shiny!: Zim has incredibly poor listening skills, and seems to retain only information he likes. "Walk for Your Lives" is probably the worst example, where Zim ignores literally everyone around him (even GIR) telling him that to speed up a time-locked, city-destroying explosion would produce... exactly that.
Dib: Zim, you're just going to blow us all up?!? This is stupid! This... is stupid stupid!
Awesome Backpack: If you don't think that a backpack with spider legs, an organ-stealing device, goggles, an entire personality and history, memories, and a hologram device isn't cool, then you need to taste some DOOM.
There's more to it. That backpack is part of what allows Irkens to live. Without it, they literally can only survive for ten minutes at a time, and it also serves as a backup brain, effectively making them amnesia-proof.
Unfortunately, according to the unaired episode "The Trial," Zim was given a defective PAK, which is the reason (or at least part of the reason) why he is so uncontrollable.
Cosmic Plaything: Sometimes. There's a good chance that circumstances will contrive to force him in the most hilariously painful way possible... then again, sometimes he succeeds and that doesn't really matter. But when his leaders want him gone, or for him to fail, it will blow up in their faces. More than any situation involving him usually blows up in someone's face, considering that it's seemingly impossible for him not to destroy anything.
Genius Ditz: It can be hard to credit, but he's demonstrated some true cunning on occasion. He's more insane than stupid, but his insanity is what makes him do stupid things in the first place, so it's hard to tell the difference.
General Failure: He really is a moron. His stupidity is usually what prevents him from conquering anything at all (if Dib or Gir has no interference). The most common assumption for this is that he carries a defective PAK, which is basically an Irken invader's brain, knowledge and competence.
Girl Scouts Are Evil: When he's selling Poop candy bars for a school fundraiser to get the mystery prize in "Door to Door".
Jerk with a Heart of Gold: Though he would never admit it, he can occasionally be a little attached to Gir. In one episode, when Gir was actually helpful, he said to himself: "Maybe that robot minion isn't so bad after all."
In another unfinished episode, he screamed in sorrow when Gir transformed into a beef.
"And besides, I promised the moon to Gir."
In "Halloween Spectacular Of Spooky Doom", he was worrying if Gir could take on all the "zombies" all by himself.
Once Zim gives Gir a lollipop when he cried, though it was mostly to shut him up.
Kill All Humans: That or enslave them — he changes it from enslaving, ruling, killing, poisoning their food supply and cutting their legs off depending on the episode. The bottom line is that the Earth needs to be ready for the other Irkens to conquer, so the humans need to be gone or easy to enslave.
Paper-Thin Disguise: Consists of a wig and contact lenses (that apparently are very uncomfortable and can be knocked out just from hitting him in the head) doing nothing about his vibrantly green skin. Which may may you think at first, since Irkens have the technology to make themselves look completely human, but he only picked that one because he thinks he's too attractive to be covered up.
Person of Mass Destruction: Tricky to place, but Zim does do a lot of damage, intentionally or not. According to the unmade scripts, he single-handedly started a crippling global blackout when he was about four minutes old. And according to that same script, he once seemingly blew up a planet just by standing there while scratching his butt. In fact, he was sent to military research because, in the words of the Tallest Miyuki (the tallest at the time) "He destroys everything he touches!"
Pet the Dog: Rather literally, Zim has had a few moments of genuine-seeming kindness directed at GIR.
Smug Snake: His super ego is what usually prevents him from succeeding, because when he doesn't have time to let his ego have any impact on his decisions, he's actually quite Badass (Especially prominent in "Hobo 13").
The Sociopath: Given that he is part of a race who's obsessed with conquering planets for petty reasons, it's not surprising. Justified still, since he isn't very good at acting out false feelings, however, the humans are too stupid to notice.
They Would Cut You Up: Zim fears this would happen if he were caught by Earth's natives. Dib explicitly threatens him with it. At one point he's seen vividly imagining his fate, human scientists stuffing him in a jar, dancing around his helpless body, cutting out limbs and eyes and keeping him a dark room for the rest of his life.
Won't Take "Yes" for an Answer: A Running Gag with him is that he'll continually interrupt people trying to tell him something, demanding they tell him about the very thing his interruption is preventing them from saying in the first place.
"Who are you?"
"I AM —"
"Who are you?"
"I AM —"
"WHO ARE YOU?"
Another is for him to randomly accuse people of lying for no apparent reason.
Zim: Hey, these [waffles] aren't bad. What's in 'em?
Zim's robot sidekick, on Earth disguised as a dog. Supposedly a "SIR" (Standard-Issue Information Retrieval) unit assigned to all invaders, but GIR is an "advanced" model the Tallest specially gave Zim. And by "advanced", we of course mean "moronic," thanks to having a head literally full of garbage.note To be precise, Tallest Purple's pocket lint. While usually too flighty to be of any consistent help, GIR will now and again go into "Duty Mode," signified by a change of eye-and-panel color from green to red, and act like a real SIR.
Ambiguous Innocence: GIR is, indeed, innocent — it is hard to imagine he even has the mental capacity to understand that there is a difference between right and wrong, much less know what that difference is. GIR often relishes in destruction only seemingly without malice, but an increase in understanding and competence (such as in the episode "GIR Goes Crazy and Stuff") would simply provide the needed motivation to apply that destructive force purposefully. In short, just because he's dumb and innocent doesn't mean he'd be a sweet-tempered do-gooder if left to his own devices.
Berserk Button: Don't make the Taco Man die in front of him, not even if it's fake.
Beware the Nice Ones: Well, technically, he is never really nice, but not really mean either... he's just selfish, and usually, he's too stupid to realize how evil he is... and when he's in Duty Mode...
Dumb Is Good: This was not the intent, but the fandom picked it up and ran with it. GIR is often misconstrued as a harmless or even compassionate character rather than a merely stupid one. "GIR Goes Crazy and Stuff" was in part a measure dedicated to correcting that.
Easter Egg: The infamous "Bloody Gir" (an image of GIR in duty mode and covered in blood), hidden as a Take That against the network for not allowing the image into a scene.
Eating Optional: being a robot, GIR doesn't need to eat, but he does anyway out of enjoyment of Earth food.
Extreme Omnivore: To name a few... A live chicken, tacos, burritos, taquitos, cupcakes, waffles made outta peanuts and soap, a fish (or tried to), pizza, Acne Blast acne cream, puppies (maybe)...
Flat Joy: This line in "Gir Goes Crazy And Stuff":
Duty!GIR: Blend in with the indigenous life, analyze their weaknesses, prepare the planet for the coming badness. Yay.
Stepford Smiler: If one is to take Word of God in the commentary of "Bestest Friends" literally, "GIR hates life and he wants to die", which would make him Type A.
His glee at being ordered to self destruct in "Dib's Wonderful Life Of Doom" seems to back this up, as does his admission in "GIR Goes Crazy And Stuff" that he even when he was normal (normal for GIR, anyways) he despised being Zim's servant.
Temporary Bulk Change: The metal he's made of is apparently very flexible because he grew to a massive size in "Halloween Spectacular of Spooky Doom" from eating the candy stolen from a bunch of trick-or-treaters.
Transformation Sequence: The first time he assumes dog form, he leaps into the air, poses amid a field of spinning bones, lets out a slow howl, and lands, picking up his costume and zipping it on snugly.
Twitchy Eye: When locked into duty mode permanently, and Zim leaves the room, you can clearly see his twitching.
Wolverine Publicity: Good god. If we had a dollar for every individual piece of merchandise that featured GIR in his dog suit, we'd have enough money to bribe Nickelodeon into uncanceling Invader Zim.
You Don't Look Like You: In the toys that feature Robot!GIR, his legs are connected to his torso instead of floating apart from it, for obvious reasons.
Voiced by: Andy Berman
"My problem is that the human race seems to want to be destroyed!"
An eleven-year-old (or thereabouts) self-styled "paranormal investigator", and one of only two people on Earth (the other being his sister Gaz) to realize Zim's extraterrestrial origin. Dib's goal is to expose paranormal phenomena to the rest of the world, but is regarded as a loon by pretty much everyone, and essentially treated like crap by the very people whose lives he's trying to save. Nonetheless, while he means well, he's fairly ruthless (at times bordering on sadistic) when it comes to dealing with Zim, making him not very highly regarded by viewers who like to cheer Zim on, but the other half of the fanbase staunchly defends his status as The Woobie.
Adorkable: His little dance with GIR near the end of "The Frycook What Came From All That Space" comes to mind.
Also, this exchange.
Zim: "Your loony "PARA-CHUTING" powers don't scare me, Dib. All it does is make you look stupid!"
Dib: "It's para-NORMAL, and you're wrong, it makes me look cool!"
Iron Butt Monkey: He has taken a lot of damage. He's been killed at least once, had his whole childhood ruined in horrible pig-related accidents, turned into bologna, turned inside out while having a hole ripped in his head...
Mr. Exposition: Dib. "Wow.....WOW! I'm boring! Do I always explain everything like that?"
The Necromancer: One of Professor Membrane's lines from "Backseat Drivers from Beyond the Stars" implies it.
"SON! There had better not be any walking dead up there!"
Noodle Incident: A Running Gag is that someone will allude to some crazy-sounding paranormal event that Dib claims to have discovered before. Given how weird this show is, it's plausible that they really happened.
Greg from the FBI: Hey...you're DIB...right? Heh-heh, you ever get that ninja ghost outta your toilet? Dib:Yes, no thanks to you!
Whatever led to Dib bringing the dead back to life the first time.
Professor Membrane: Son, there better not be any walking dead up there! Dib: It's nothing to worry about, dad! And I said I was sorry about that!
Then there was this little gem in "The Nightmare Begins":
The Letter M: Yeah, what's wrong with you? All you talk about is aliens and ghosts and seeing bigfoot in your garage! Dib: He was using the belt sander...
Don't forget whatever gave the Mysterious Mysteries host his scar. Speaking of which, the Mysterious Mysteries host has an entire room (apparently very large) that's overflowing with reports from him, which he lives in mortal fear of having to visit. Honestly, it's probably safe to say that Dib's entire life is one big Noodle Incident.
Not-So-Imaginary Friend: Given the sheer weirdness of Dib's world, it's very plausible that Dib really has seen all the paranormal craziness he claims to have seen — in "Bad, Bad Rubber Piggy", we actually see Dib trying to catch what is quite clearly a baby Sasquatch, despite its own claims of being a human kid. Not to mention the whole thing about Zim really being an alien, even though nobody believes or recognizes it.
Only One Name: Played with. At one point, he is addressed as "Dib... Whatever your last name is," and Dib says that's correct.
Only Sane Man: Which is saying something, as he sometimes seems not entirely sane himself.
Parental Neglect: Although it's more workaholic neglect then outright abandonment, Membrane scarcely acknowledges him.
Vocal Evolution: Andy Berman couldn't seem to make up his mind: in some episodes, Dib sounds like he did in the premiere (more nasal and fast-paced), and in others, Dib's voice is much rougher and lower, and he talks more slowly. The latter voice makes him sound more teenaged.
"What you need is to give the Game Slave to me or I will plunge you into a nightmare world from which there is no waking!" (after getting a negative response): "I hope ya like NIGHTMARE WORLDS!"
Dib's younger sister. Like Dib, she knows Zim's real origin, but unlike him, she doesn't much care, on the grounds that he really isn't very good at the whole world-conquering thing. That, plus she seems to be something of a misanthrope herself. (She did once have a very hard time deciding whether to destroy all life on Earth or not, when putting a can in a super-powered microwave.) Mostly Gaz sticks to her video games and snarks at the insanity around her.
Actually Pretty Funny: She's laughed at some of the stunts Zim's pulled on her older brother. Oddly, her saying this line near-verbatim after one of Dib's stunts proved unexpectedly hilarious was one of the closest things she's had to a Pet the Dog moment with him.
Disproportionate Retribution: Particularly in the episodes "Game Slave 2" and "Battle-Dib", Gaz is prone to waging all-out war against those who cheat her of what is rightfully hers... even if it's just a pizza or a gaming console, it's Serious Business.
Only Sane Girl: She is one of the few people who know perfectly well that Zim is a alien who wants to conquer/destroy the Earth. She's also largely uninterested in the conflict, quipping rather correctly that Zim isn't very good at what he does.
Pet the Dog: Her moments of this are so noticeable because they're so *** rare; it almost seems out-of-character when it happens!
Voiced by: Wally Wingert (Red), Kevin McDonald (Purple)
"The universe will be ours for the taking! It's only a matter of time before all the races of the Universe serve the Irken Empire!" "I'll have them serve me curly fries."
The leaders (or more accurately, figureheads) of Irken society. Their height being the only qualification for office, they're not necessarily well-equipped in the brain department, although Red does seem to have it together more than Purple. Pretty much they sit around snacking and acting like jerks. Their role can be likened to a pair of teenage bullies picking on and ordering around a bunch of smaller kids.Red and Purple weren't the first Tallest. Some of the previous leaders were slated to appear in flashbacks if the show hadn't been canceled.One should address the Almighty Tallest respectfully as "My Tallest", the equivalent of "Your Majesty" (or, more appropriately, "Your Highness") on Earth. As a general rule of both grammar and respect, "My Tallest" is never pluralized, even when two Tallest rule in tandem.
Brilliant, but Lazy: In certain situations Red shows himself to be quite competent, however he seems to prefer not to have to exercise his intelligence, instead allowing underlings to handle problems for him in all instances save those in which his personal safety is being directly threatened.
Butt Monkey: Purple to a degree, mostly due to Red's abuse of him.
The Caligula: Both of them, although Purple is especially useless.
Culture Clash: They are utterly baffled when Zim explains to them that adult humans are generally a lot taller than Irkens, but are also on average incredibly stupid. Since this goes directly against the ideals of Irken society, the Tallest have trouble wrapping their minds around it.
Deadpan Snarker: Other than hysterical laughter or blank shock, their usual reaction to Zim's antics.
Zim's base explodes during a videoconference
Purple: Well, you look real busy exploding, Zim...
Red: What a shame, moving on now...
Divergent Character Evolution: In the first episode they each got alternating moments of stupidity and intelligence. By "Backseat Drivers from Beyond the Stars" Red seems to be the smarter one, though he still spends plenty of time acting lazy and stupid along with Purple.
Evil Empire: They are the figureheads of the Irkan Empire.
Faux Affably Evil: They're lazy and generally genial, but that won't stop them from committing genocide or jettisoning their own soldiers for not being tall enough.
Fingore: They only have two fingers on each hand as opposed to a normal Irken's three. According to the Zim wiki, when a Tallest is chosen, their thumbs are chopped off in a ceremony to prove that they can rule without them.
Younger than They Look: They look older than Zim, but the script for the unproduced episode "The Trial" reveals that the three are about the same age.
Voiced by: Roger Bumpass
Friend to the world, enemy of Santa Claus.
The father (at least allegedly) of Dib and Gaz, Membrane is a scientist who also hosts the Show Within a ShowProbing the Membrane of Science. He keeps a very busy schedule, to the point he can only manage to eat dinner with his children once a year.
The Ace: With as often as he's used for comic relief, it can be easy to forget that in the universe of the show he's the most well respected scientist on earth and for good reason.
Arbitrary Skepticism: He refuses to believe any of Dib's paranormal claims, but he does believe in Santa Claus. (Then again, so does everyone else.)
Anti-Villain: She doesn't seem to be outright evil, just extremely nihilistic and apathetic, and doing what's necessary to keep the Skool in check.
Even Evil Has Standards: Despite the obvious hatred she has for her students and all the horrible stuff she's told them before, she refused to divulge just what happened that led people to start giving out meat on Valentine's Day. Her response to Dib's question was "you don't want to know". She even expressed "moral outrage" to the principal allowing the kids to celebrate the holiday.
Evil Old Folks: While not evil per sae, she's cantankerous and lives up to her name.
Badass: He's the first Irken Invader to single-handedly complete his mission, and he survived being on a planet as it was being blown up. If it wasn't for his gullibility, he'd be an Irken to be reckoned with.
"I should have been an Invader! I should have been part of The Great Assigning! I shouldn't have to be stealing this planet from you!"
A female Irken out to seek Zim's mission and prove herself as a worthy Invader to the Tallests. Fifty years ago, Zim caused a blackout that caused her to miss her test to become an Irken-Elite. Not to be confused with the main character of another Nick franchise, Tak and the Power of Juju.
Best Served Cold: Tak wants to conquer Earth before Zim, since Zim was the one who made her fail her military exam and sent her to work as a janitor (on Planet Dirt) for fifty years. She actually doesn't view it as revenge so much as setting things right, though—-as she (correctly) points out, she's a highly competent invader who deserved to get assigned a planet, while Zim was sent there just to get him out of the Almighty Tallests' antennae.
Butt Monkey: Somewhat, particularly being exiled from her planet despite being an excellent invader but Zim's idiocy caused this, and getting thwarted by Zim and being almost killed in a spaceship crash. Tak just couldn't catch a break.
Cats Are Mean: Her S.I.R. Mimi takes the guise of a cat, and is nasty powerful enough to kick Zim and GIR's asses.
Hypnotic Eyes: Tak seems to possess these in the form of some sort of device in or near her eyes. While in disguise, a flash of her eyes allows her to erase short-term memories of her victims (unless their mind is too strong, like Dib's and Gaz's were) and, in one case, impose her will over others.
Girl: Looks like Zim has a girlfriend!
Tak: It's not NICE... to embarrass people! You should apologize... and... [eyes flash] eat your eraser!
Girl: (With Mind-Control Eyes) Yes, Tak! I'm sorry, Zim. [Takes a bite out of her eraser]
Character Development: It's only in one episode, but you can still kinda see Lard Nar come into his own over the course of "Backseat Drivers" — from a guy who completely freaks out over the slightest setback, to a leader undaunted at even the loss of his entire ship.
One Shot Characters: They were meant to be more, but the show was cancelled before their plotline could get past its introduction. Lard Nar does show up in a non-speaking role in the unproduced script for "The Trial."
"We will take your ship! And for the trouble you've caused, we're going to destroy your base, leaving you stranded here. Just like we were."
A race of aliens led by Gorkspace Sergeant Shnooky who were stranded on Earth posing as human babies after an incident in a maternity ward. They attempt to take Zim's ship and use it to fly back to their home planet. It doesn't end well for them.
"Nobody escapes from Sizz-Lorr. I will find you, Zim. I will search all of space's dark corners to hunt you down.AND I WILL FIND YOOOOOUUUUU!!!"
Zim's boss during his exile on Foodcourtia, an Irken frycook who runs Foodcourtia's premier restaurant. After Zim escaped the planet, Sizz-Lorr swore to make him come back if it was the last thing he did.
Badass: Proves himself to be one in the climactic scene of The Frycook What Came From All That Space.
Bad Boss: He was like this to Zim even before the latter ditched him on Foodcourtia and left him stuck there for 20 years. Well, Zim was already there in exile.
Kids Are Cruel: Miss Bitters' class could give Gaz a run for her money in this department. The only ones to be exempt from this are Gretchen, Keef and a handful of recurring kids who don't pick on Dib.
Even Gretchen is seen laughing at Dib in "Room With a Moose" and "Frycook What Come From All That Space."