May I present…

The Invader Gir AU!

An AU where everything is the same except Gir is the irken Invader sent to conquer Earth and Zim is his trusty SIR unit. HOWEVER

He’s not really an Invader and Gir actually got himself willingly banished to Earth. Although he can be incredibly competent and efficient when he wants to be, and thus made it through his military training, he would much rather have fun and be silly, which he knew he could never do as a “proper” member of irken society. So he intentionally planned things so that he would become an Invader but then annoy the Tallest so much they decided to banish him to a far off world with no intention of actually conquering it. He was fine with this.

But they didn’t send him alone. Oh no, they decided to give him a SIR unit. Specifically, they gave him a decommissioned model that was known for being violent, overzealous, and would actually try to take over missions from their masters if they thought things were proceeding too slowly. What can I say, the Tallest are assholes and didn’t want to give an exile the most top of the line model. Gir is nonetheless happy for the companionship and names the robot Zim.

Unfortunately, while Gir quickly immerses himself in human culture and enjoys living a free life the way he’s always wanted, Zim refuses to believe that they were sent on an intentionally doomed mission. He frequently tries to goad Gir into weakening Earth and preparing it for invasion by the armada, and when Gir shrugs off such attempts and tells him they’re here permanently, Zim just takes things into his own hands and carries out his own plans to conquer Earth.

Luckily he’s not very good at actually accomplishing such plans, but he does tend to cause a lot of localized destruction. Gir hardly seems to notice, only getting onto Zim when the plan of the day interferes with Gir’s fun. Gir is too forgiving to really resent Zim for anything, but over time Zim grows frustrated with his master and begins to view him as incompetent, so he becomes even more determined to do what he was programmed to do. No matter what it takes, he would bring the Armada to Earth

oh and Gir is completely open about being an alien on Earth, like he attends the local school just to learn things and make friends, and doesn’t even bother with a disguise. And when Dib inevitably accuses him of being an alien, he just grins and chirps, “Yep!” and Dib has no clue what to do from there

also Gir and Keef almost immediately become best friends. And if you’re wondering about Gir’s robotic left arm, he’s very accident prone so he lost his arm in an accident when he was young, and they just gave him a robotic arm because it’s easier than regrowing an entire biological arm. He’s quite fine with it and by the time he gets Zim, he’s happy to show off how similar they are. Zim is not at all impressed.

so yeah that’s the Invader Gir AU haha enjoy