- "Once I escape, I will replace each of your organs with explosives and rubber worms!"
Zim is a small humanoid alien with green skin and big pink eyes, he has two antennas going from the back of his head. Zim is dressed in a red and magenta bodysuit with grey gloves and black boots. He wears a black belt with the letter V on it.
Zim is very cocky, impatient, incompetent, and confident individual. Zim is known to be very perseverant, as he has been known to fail over and over and still not accept defeat. Zim's primary desire is to conquer Earth, mostly to prove his superiority and impress his leaders. Zim is an overall fairly unsympathetic character. Zim also lacks much understanding of Earth culture. He frequently insults anyone around himself with words that usually make no sense when paired together in the English language.
- PAK- The PAK Zim uses has a variety of uses such as 4 spider legs, A jetpack, and etc.
- IRKen Gun- Zim carries an Irken weapon, a gun that shoots disintegrating lasers.
- Above Human Intelligence- Because Zim is an Irken and has lived for an entire century, he has an intelligence highly surpassing one of an average human.
- High Pain Tollerance- Zim is able to withstand high amounts of pain and agony, far beyond what a Human could handle without dying. Everything from being burned, electrified to even having some of his organs removed and simply attaching them back.
- Irken Size- Zim is incredibly small & fragile, as a result of his race and him being a defect.
- Water- Zim's skin is sensitive to water, allowing him to be burned by any type of contact. He avoids this weakness by covering himself in a layer of waterproof paste.
- Meat- Zim has a weakness concerning most Earth meats, as they burn his flesh when making contact with him.
- PAK Damage/Removal- If Zim's PAK would be removed from his body, he would die in 10 Minutes. Due to his PAK being connected to his nervous system, this makes him highly susceptible to technopaths.
- Overconfidence- Zim's ego is by far his greatest weakness, as he has been on the verge of victory, only to allow his pride or self esteem to force him into making mistakes and ruining his own plans.
Zim was an Invader of the Irken Armada until the day when Operation Impending Doom began. On that day Zim ruined his leaders' plans by attacking his own home planet thinking it was his assigned planet to conquer. After this setback Zim was banished to Foodcourtia and was reassigned to be a food service drone.
After he found out that Operation Impending Doom II was about to begin he "quit being banished" and left Foodcourtia to go to Conventia for The Great Assigning. After when Zim showed up his leaders "The Almighty Tallest" were displeased to see him again. So in a effort to get rid of Zim, The Tallest sent him to an unknown planet. And they gave Zim a broken SIR Unit.
After 6 months of flying though space, Zim arrived to the unknown planet and discovered it to be Earth. Zim then began his mission to eradicate the human race for the Irken Empire.
- Zim first appeared in Chapter 3: Reunion (Page 4), commanding an escaping GIR outside a Plumber base (Orion-Cynus District) and transporting him to Zim's house with the 'information'.
- In Chapter 4: The Fallen Gods (Page 11), Zim reappears in a monitor screen in his house in his own dimension giving Eon GIR to examine the information that he took. Eon later explains why he is there, which is 'providing a base of operations, and technology that would be an obstacle to obtain'.
- In Chapter 6: Weightless (Page 4 - 27), Zim worked on draining the power of the Dwarf Star whilst The Alliance battled the Plumbers and Danny Phantom. With the heroes noticing Zim draining the Dwarf Star, Ben Tennyson transformed into Lodestar, who promptly destroyed Zim's Massive. Left stranded in space, Zim was captured by Gwendolyn Tennyson, who saved him from the black hole created by the collapse of the Dwarf Star.
- In Chapter 7: Fold (Page 10 - 14), After Zim was captured by Gwen, he was held prisoner inside of the Plumber Ship's hatch. Ben then transformed into Pesky Dust and look at Zim's memories.
- In Chapter 9: Time Out (Page 36), he was teleported to The Ghost Zone by Divinity while prisoner aboard Rook's ship.
- Chapter 3: Reunion (first appearance)
- Chapter 4: The Fallen Gods
- Chapter 6: Weightless
- Chapter 7: Fold
- Chapter 9: Time Out
- Chapter 10: Again
- Zim's involvement in the 5YL storyline was kept a close secret from the majority of fans before his reveal at the end of Chapter 3.
- Zim is an antagonist in 5YL despite being the protagonist of his own show. This is due to the fact that Zim's anti-villain role in his own show gives him a villain role when facing heroic protagonists.
- Due to the movie Invader Zim: Enter the Florpus giving Zim's show some justice, Zim's role was reduced in 5YL.
- Zim is the genetic donor for Ben's transformation Lank.
- Upon Zim's capture, the Plumbers confiscated Irken technology from him.