GIR
GIR is Zim’s dull-witted robot.  All the normal Irken invaders got a SIR – Standard-issue Information Retrieval – unit.  Zim got GIR.  GIR was made quickly by the tallest out of garbage.  So why is he named GIR?  Well, no one knows for absolute certainty what the “G” stands for, but it probably stands for “Garbage”, making him Garbage-issue Information Retrieval.  It makes sense.  Anyway, as you may have realized, GIR’s not really very smart.  He drove Zim crazy on the way to Earth, by singing the Doom Song for six months straight.  When they got to Earth, GIR wanted to be disguised as a mongoose, but Zim thought he’d be better suited as a dog.  So, GIR has a dog costume.  A green dog costume with an obvious zipper going right down the front.  Oh but, you’re crazy if you think no one notices.  GIR even tends to go out and buy slushies!  But then again, GIR also tends to let Dib and Gaz into Zim’s secret base….
"I wanna be a mongoose!"

Dib
Dib is a human boy who has been prodding the paranormal almost all of his brief life.  He lives with his sister, Gaz, and his dad, Professor Membrane.  He was just your normal, every day junior paranormal investigator, until one day, a green kid named Zim entered his class.  Dib instantly knew Zim was an alien, but none of the other kids in his class believed him.  They all think he’s crazy.  Dib’s father, the scientist, even thinks he’s crazy.  Gaz just thinks he’s stupid.  Despite all this, Dib still has completely devoted himself to stopping Zim’s conquest of Earth at all costs, not to say he won’t pass up any other chance to research paranormal activity.
"Okay... am I the only one here who sees the alien sitting in class?"

Gaz
Gaz is Dib’s little sister.  She doesn’t care about him though.  She believes he’s stupid and doesn't want to help him defeat Zim either, because she knows that they’re both equally stupid and Zim will never successfully conquer the earth.  Besides, she’s too absorbed in her video games to care about anything else.  Gaz is usually playing her GameSlave no matter what else is going on around her.  The only other thing she does care about is spending time with her dad, since he’s such a busy scientist and she barely ever gets to see him.
"Dib drank the last soda.  He will pay!"

The Almighty Tallest
The Almighty Tallest, Red and Purple, are the two leaders of the mighty Irken race.  Why?  ‘Cause they’re the tallest, duh!  Yes, the Irken social system is based on height.  Anyway, the Almighty Tallest are the ones who chose the invaders and sent them out on their separate tasks.  But when Zim came along, they weren’t sure what to do.  They figured that if they would just send him to some unknown planet he would probably never find, all their problems would be solved.  They were wrong.  Zim found the planet, so now all they can do is not help him and laugh at him behind his back.
"Besides, no invader has ever been so... very small.  You're very small, Zim.  You're a tiny thing."

Robot Parents
These are two robots that Zim created to pose as his parents.  They don’t do a very good job of it, though.  They almost completely exposed Zim on Parent-Teacher Night.
"That was my squeezin' arm.  They took my squeezin' arm!  Why my squeezin' arm!?  Aaagghhhhhh!"

The Scary Monkey
The Scary Monkey is a very special monkey.  In fact, this monkey is the star of his own TV show; The Scary Monkey Show!  Not only does this show have a monkey, but it’s GIR’s favorite show, showing how great it is.  Also, reports indicate that the Scary Monkey has been spotted at Zim and Dib’s local mall.  Hmm…
"Grrrrrrrr..."

Bill
Bill is the paranormal investigator that Dib was paired up with for Career Day.  At first he seemed sane… then he proved us wrong.  He calls himself a paranormal investigator, but he goes chasing after fictional characters, such as Count Coco Fang.
"The aliens must be controlling the cow somehow...."

Tak
Tak is an Irken who was training with Zim to become an invader.  Unfortunately for Tak, Zim accidentally knocked out the power on half of the training planet, causing Tak to miss her test.  Tak then set out to find Zim and make him pay for ruining her life.
"Maybe you really are an alien like Dib says.  A horribly disguised, disgusting, horrible one."

Invader Spleen
Invader Spleen was one of the Invaders in the Great Assigning.  Little is known about him, only that he has a very large head, which had a Band-Aid on it at the Great Assigning.

Slab Renkle
Slab is a night-shift security guard at the local mall.  When Zim breaks into the mall at night to return a video disk, Slab tries to get rid of him.  Then he captures Zim and sends an army of zombies after him and stuff.  Bottom line: Slab Renkle is insane.
"Oh, you're dealing with someone far worse than the FBI.  You've just crossed... mall security."

Keef
Keef is one of the rejects in Zim's class.  Except at one point, when Zim thought he needed a friend to keep people believing he was human, so he befriended Keef.  But when Keef keeps hanging around Zim when Zim wants him to go away, Zim has to get rid of Keef.  He basically makes Keef think that A squirrel is his best friend.  Keef never bothered Zim again after that.
"I have a great idea, GIR!  I think we should throw our Zim a surprise party!  It'll cheer him up!"

Bloaty
Bloaty is the mascot of the Bloaty's Pizza Hog pizza restaurant.  He's a big fat guy in a big, disgusting pig costume.  Bloaty has been seen not only in numerous commercials for Bloaty's Pizza Hog, but also in the restaurant itself.  In fact, his many layers of fat saved Gaz's space ship from crashing after she went to rescue Dib from Zim's grasp.  Hooray for Bloaty!
"Oooohhhhhhh... I eat too many pizza...."

The Rubber Piggy
Ah, the Rubber Piggy is the best of them all!  It's a little rubber piggy toy that GIR loves and loves to play with.  He actually had many rubber piggies at first, but most of them were sent back in time, so now he only has this one.  The Rubber Piggy's great.  It's even been to Mars!

Agent Darkbooty
Agent Darkbooty is part of the Swollen Eyeball, the paranormal club that Dib is in.  Strangely enough, Agent Darkbooty is actually an old janitor guy in NASAPLACE.  He helped Dib get to the Butt on Mercury, by giving him one of the old monkey ships that he had repaired.
"It's one of the old monkey-ships from when they used to send monkeys into space.  Mmmmm, you can still smell the monkey."

Peepi
Peepi is the hamster that Zim's class got as a class pet.  Zim was amazed at how Peepi's cuteness made the humans weak, so he decided to turn Peepi into a giant mutant hamster that would terrorize the city for him, and the humans would be defenseless against the cuteness of the hamster.

Ms. Bitters
Ms. Bitters is the teacher od Zim and Dib's class.  She's a very scary old lady, almost ghost-like in some ways.  She believes that everything is horrible, making most of her lessons not very meaningful to her students.  One example is when she decided to have a quiz on the copyright information of the students' textbooks.
"Today's lesson is about something horrible.  Now, open your horrible textbooks to page 2,038."

Old Kid
Old Kid is actually a little old man who is sometimes in Zim's class.  The students don't seem to notice that he's an old man, though, so they accept him as his own.
"How's it goin'?"

Future Dib
This isn't actually the Dib of the future.  It's really a robot that Zim created to trick Dib into thinking it was him from the future.  Zim later uses the robot to try and break into Professor Membrane's Perpetual Energy Generator, but he fails when Gaz beats up the robot for acting crazy.
"It sure was crazy!"

Interactive Instruction Manual
He's the last of the Marsiods, and he's only the interactive instruction manual to the planet Mars, that his people worked themselves into extinction turning it into a navigable space vessel.  According to the IIM, the Marsiods did this only because it's kool.  Oh, also, his head's so big it couldn't all fit on the screen at one time....
"I am all that is left of my people.  An interactive instruction manual for the incredible vessel you are now helming."

Nightmare Gaz
When Zim and Dib go into the horrible nightmare dimension, they see nightmare versions of people in the real world.  When Dib goes into his nightmare house, he finds Nightmare Gaz.  Nightmare Gaz is sipping from a juice box as she laughs evilly.
"We're gonna open your head!"

Nightmare Membrane
Nightmare Membrane was also in Dib's nightmare house when he went into it.  Nightmare Membrane grabbed Dib and brought him back to Nightmare Bitters.
"Whoo, I'm floating!"

Nightmare Bitters
Nightmare Bitters is the leader of all the nightmare creatures.  She organized and was the boss of the whole operation for the nightmare creatures to escape into the real world through Dib's head, though when she got to the real world, she couldn't stand it because all of the children in Halloween costumes were too disgusting for her.
"Let the head... thingy... start!"

Lizard Boy
Lizard Boy is a student that goes to Zim and Dib's skool.  He is known as Lizard Boy because he has a tendency to stick out his tongue in a lizard-like manner.  He was once seen with a glass in his mouth and his tongue shooting out in the glass.

Brian
Brian is a student in Ms. Bitters' class.  He sits next to Zim.  Brian didn't believe Zim was an alien, but on Halloween, he did think Zim was crazy.  On Valentine's Day, Ms. Bitters decided she was tired of Brian, and she sent him to one of the "underground classrooms".  He died down there, so Poonchy: Drinker of HATE took his seat in class permanently after that.
"Zim's bein' kinda wacked, yo!"

Invader Skoodge
Invader Skoodge is one of the Invaders from the Great Assigning.  But because of his extreme shortness, he was sent to Blorch, home of the slaughtering rat-people, to try to conquer the planet.  Well surprisingly enough, Skoodge was the first Invader to conquer his planet!  But since the Almighty Tallest hated him so, they put him in a giant cannon and shot him away.  But remarkably, he survived.  He came back later on Hobo 13 to train with Zim's squad, believing that the Tallest would reward him if he succeeded.  Unfortunately for him, he was carried away by the Sergeant as he was carried away by the Hogulus and hasn't been seen since.
"Zim!  I escaped from the canyon!  I'm alive!"

Mimi
Mimi is the name of Tak's SIR unit.  Mimi looks different from most other SIR units, probably because Tak must have either made Mimi herself, or done some major enhancements on her, because Tak didn't have any access to a regular SIR unit.  Mimi can disguise herself as Tak's cat, by use of a hologram, a much more convincing disguise than GIR's.

Krazy Taco Mascot
This would be the mascot for the Krazy Taco fast food taco place.  He's a guy in a big taco costume.  He seems to have a few mental problems, as indicated in the Krazy Taco's commercial, where he does seem to be a little, um... crazy.  Not to mention the fact that he thought he'd turned into "Tacofoot"....
"Oooohhhh!  I'm a taco!"

Chickenfoot
A real urban legend, kinda like Bigfoot... no wait, this is just a moron in a chicken suit.  His real name is Chuey Rodriguez, and he used to be an employee at a chicken restaurant called Chicky Licky.  But one day, after some mashed potatoes hit the microwave and it exploded, Chuey gained the strange delusion that he had become half chicken.  He had ever since been living on the outskirts of town, believe he is a "chickeny man".  That is, until Dib come along and eventually gets that smelly old chicken suit off of him.
"Don't look at me!!"

Mr. Elliot
Mr. Elliot is the Teacher of Gaz's class.  He also seems to be a former student of Ms. Bitters.  There's not really too much more to say about him, actually.
"Hello, Professor.  I'm Mr. Elliot- your daughter, Gaz's teacher."

Minimoose
Ah, Minimoose.  The character that mysteriously appeared in the show one day.  Actually, in an episode that won't air, ZIM creates Minimoose to replace GIR.  See, Dib had said something like, "If you're from such an advanced alien race, then why is your robot so stupid?"  This made ZIM decide that he needed a new sidekick, so he created Minimoose: a super moose-like thingy with an evil doomsday device.  Unfortunately, Minimoose's doomsday device never really worked, so now he just kinda floats around ZIM's house and helps him with various tasks.
"*SQUEAK!*"

Pig
Pig is GIR's best friend.  GIR likes to have Pig- who, by the way, is a pig- over to play and have tea parties and stuff.  They're an adorable pair.

Do you know of another Minor Character you'd like to see on this list?  E-mail me and I'll post them here!