This is my take on an Invader Zim AU. Here, Zim is labeled as defective far earlier than the series and he is marked for destruction by the Irken Empire. This AU begins about 2 earth decades after Zim's trial, and Zim has been on the run the entire time, looking for some place where the Irkens will never find him…
xXxXx
I have to get away! The Spittle Runners! They're closing in! GIR! Get away from the weapons console! We need to fight back or we're burnt space toast! No! To late! Eh? We're hit! Well, only one option now!
Sir. I don't believe activating the hyperdrive in this condition is a good idea.
You dare inform me of what I already know! It's our only choice!
YAY! WE'RE DOOMED!
Nyeah!
xXxXx
Dib Membrane sat on top of the shed in the backyard, staring up at the sky, the stars reflecting off his large, round glasses. He could get lost in these stars for hours. Unfortunately, his family didn't accommodate for this.
"Dib! Dad says come in for dinner!"
That was Gaz, his sister. Her squinted, amber eyes glared up at him from under her purple bangs.
"Ask him if I can stay out just a little longer."
"He thought you'd say that, and he said get in there now!"
"Fine," Dib sighed. "I'm coming."
Dib slid down the water spout and walked across the yard towards Gaz. Suddenly, a loud explosion shook the ground, causing both of them to stumble. Dib looked up to see some kind of spacecraft, engulfed in flames, imbedded into the yard were he had been standing just a moment ago. The large, round windshield opened, and pinkish smoke billowed out. A moment later, to eyes, each one a bright ruby color, locked onto them. Soon, a small, green head followed the eyes and a strange creature staggered out of the wreck. It stared at the human children for a moment, before its eyes went vacant and its body went limp.
xXxXx
Slowly, the alien opened it's large eyes and looked around. First off, his ship. The fire was out, and the damages were not beyond repair. Second, he seemed to be in some kind grassy courtyard. Thirdly, and most alarmingly of all, he was tied up with a leather belt and two creatures he did not recognise were staring at him.
"Insolent creatures! Unhand Zim!"
"I can't believe it, Gaz! A real alien!" Dib cleared his throat and turned to Zim, trying to look intimidating. Gaz scoffed and rolled her eyes.
"So, Alien. Why did you come to earth? To enslave humanity? To eat our brains? Answer me!"
Zim laughed. "I assure you, dirt-child, I came to this mudball completely by accident. As you can see by my ship, I was under attack."
Zim looked around before nodding, a huge, zipper-toothed grin spreading over his face.
"Y'know, this place is very far away from Irk. It's not even on any known maps. Yes, this could work."
The small alien turned his attention to the humans, who were watching him curiously.
"I have decided! Dirt-babies! You shall be my guide to this planet while I hide here! Another expertly crafted plan by ZIM!"
"Hold on! What makes you think we're going to trust you? We don't know anything about you! How can we be sure that you won't try to eat our brains or whatever?"
Zim looked confused for a moment, before a smirk crossed his face.
"Y'know, you creatures are more cautious than you look. Or maybe you're just a special case. Either way, I have no allegiance to the Empire anymore, and if you release me I am willing to answer any questions you may have."
Dib thought this over. Was he really willing to let this alien… thing… loose just in hopes of a better understanding of the universe? He might be dangerous. He might hurt people. But when would he ever get another chance like this? It was so tempting. Finally, he caved.
"Alright. C'mon, you."
Once he was untied, Zim got to his feet and stretched a bit. Surprisingly, he had no injuries from the crash, though his uniform was in tatters. He would have to ask the dirt-babies for spare clothing. In the meantime, they would need to blend in, and he had just the thing.
"GIR! Minimoose! Get out here!"
Out of the smoldering ship, two robots emerged and stood before them. One was a typical robot, shaped not unlike a human. It was small and stared at the humans with vapid fascination with two glowing, blue eyes. The other was shaped like a small purple moose. It was totally wall-eyed and floated about three feet off the ground.
"I have decided that we will be hiding on this planet for a while, which means we will need disguises."
Zim tapped his finger against his chin before turning to Dib.
"Do you have moose-creatures on this planet?"
Dib nodded and Zim said, "I guess you're okay then, Minimoose."
The tiny moose squeaked in response and floated back towards the ship. The diminutive alien marched to the back of the ship and pulled open a console with a selection screen on it.
"Computer! Prepare disguises for Earth creatures!"
The screen instantly filled with a list of human costumes. Zim swiped through them until he came to one that was simply a wig and a pair of human-like contact lenses.
"That one looks good."
"That one?" Gaz asked. "You're kidding, right?"
"DO NOT QUESTION MY METHODS!"
Zim clicked on the chosen disguise and the two pods on the sides of his ship lowered, closing around him, and began vibrating.
"AH! OOO! WHY DOES IT HURT?!" Zim screamed from inside.
After a moment, the pods opened again, revealing Zim in his new disguise.
"Master! Where did you go? Where are you?"
"I'm right here, GIR! It's me!"
Zim then grabbed hold of GIR's arm and led him to the pods.
"Alright, for you, I'm thinking maybe a dog."
Zim selected a random breed on the screen and the pods closed around GIR. After a moment, the pods opened to reveal GIR wearing a poorly-made, green dog costume with a zipper clearly visible and two large, glassy eyes.
"INGENIOUS! Now, we-"
"What is going on out here?"
Dib and Gaz's father, Professor Membrane, came out of the house and stopped dead in his tracks at the sight of the smoldering vehicle and the green stranger in his backyard.
Dib reacted first.
"Uh-we-uh… Dad? This is our friend, Zim. He accidently crashed his… go-kart in our yard. Is it okay if he spends the night with us?"
Membrane's confused face quickly turned to one of happiness.
"Well, of course! Look at my children making friends! Just make sure you clean up the yard, okay?"
As he walked back into the house, Zim, Dib and Gaz all released a breath they didn't realize they'd been holding.
xXxXx
Dinner was eaten mostly in silence, with a little conversation between the Professor and Zim here and there. Professor Membrane seemed to really like the strange, green boy sitting at his table, and his children were just glad that he didn't seem to find anything unusual about him.
After dinner, Dib led Zim, GIR and Minimoose to his room while Gaz went to her room to play video games.
"We'll have to get you out of those rags. Here, let me get that for you," Dib said, grabbing hold of Zim's metal backpack.
Suddenly, he found himself pinned to the ground by four, long metal legs protruding from the aforementioned backpack and Zim right above him with a look of pure rage stretched across his features.
"You dare try to remove Zim's PAK? After our truce, you dare try to kill me?!"
"What are you talking about? What did I do wrong?"
Zim's rage slowly melted from his face. He got back up and the spider legs retreated back into his PAK.
"No, you're right. You couldn't have known about that. Escentially, this PAK is my battery life. If I'm without it for more than ten of your earth minutes, I would die a slow, painful death."
"I-I'm sorry," Dib stammered. "I didn't know."
"Eh. It's fine. Nothing happened."
"Here," Dib said, handing Zim a purple hoodie and some sweatpants. "I think this will fit you."
Zim gasped. "IT'S PURPLE!"
"Do you… like purple?"
Instead of answering, Zim slipped out of his tattered uniform and threw the hoodie on over his head. After a moment, his smile faltered and he lifted the hoodie back over his head and turned his back to Dib.
"Is something wrong?"
"No, Dib-creature. I just need you to hold my PAK for a second."
Dib did a double-take. "But didn't you say you'd die if-"
"It'll be fine. It's only for a few seconds and I need to put holes in the hoodie for it."
Dib did as he was told and placed both his hands on the sides and the PAK popped off in his hands. Zim shuddered for a moment, but slipped the hoodie back over his head without further complaint. Once he did, two small mechanical tentacles shot from the PAK, cutting two perfect circles into the back, before reattaching itself to Zim's spine.
"Are you okay?"
"Of course I'm fine. I AM ZIM!"
Dib chuckled a bit until something came to him.
"Hey. You said before that you wanted to hide here from someone."
Zim suddenly looked a little uncomfortable.
"Yes, I said that."
"Who were you hiding from?"
Zim sighed and sat down next to GIR at the foot of Dib's bed.
"The Irken Empire."
xXxXx
Well, how was that. In case it wasn't obvious, I got the idea for this AU from reading Issue 37 of the Invader Zim comic series, where Zim traps Dib in his holochamber and used it to create a world where he was an official member of the Membrane Family, and I thought the idea of Sibling Zim was just too cute not to have an AU based around it. Let me know what you think in the comments and I'll see you all next time.