#any other irken would have failed because nothing short of a holographic disguise will fool Dib

[random-iz-stuff]

Any other irken would have failed at conquering earth or even living there for an extended period of time.

Having poor quality disguises that somehow work anyways isn’t a thing that only Zim goes through. All irken invaders besides Tak use terrible disguises that somehow work despite it barely changing anything, so being discovered by Dib is basically inevitable. But the reason that Zim survives when other irkens fail chalks up to how they deal with Dib, since he’s the only real threat on earth.

Any other invader would have looked at Dib and completely underestimated him. Either ignoring him because no one will believe a young child in this situation or capturing and killing him not because he poses an actual threat to the mission, but because he’s annoying and keeps getting in the way. And that is their fatal mistake.

If you ignore Dib because he isn’t a threat, he will end up getting proof somehow and your cover is blown because Dib is the son of the greatest scientific mind on earth, meaning that he has access to advanced (at least by earth standards) technology and a large amount of people that he can show his findings to because you can’t tell me that the Son of Professor Membrane discovering solid proof of extraterrestrial life won’t end up on the front page of at least one newspaper.

If you remove Dib from the equation by kidnapping and/or killing him, you now have to deal with Professor Membrane, Gaz Membrane and the local police busting down your door because you can’t kidnap the oldest child of one of earth’s most well known celebrities without drawing a whole bunch of attention to yourself and there’s no way that Professor Membrane wouldn’t be able to find Dib’s location using the power of science.

Fully functional Irkens don’t have very good imaginations or a very good ability to think outside the box. When faced with Dib, they will always choose to either ignore him or remove the threat as soon as possible because that’s what you’re supposed to do as an invader. You sneak onto the planet, remove all potential threats and begin your takeover when nothing is in your way. That’s how it’s taught in the military so that’s how it’ll be done.

Zim on the other hand, doesn’t have a fully functional PAK restricting his thoughts and seemingly refuses to think inside the box. He dealt with Dib by recognizing that he was a threat early and instead of killing him, which would risk drawing attention to himself, he kept him alive and simply rolled with the punches. Any attempts to kill Dib are made to look like accidents and/or can’t be traced back to Zim. Sure it gave him some extra work, like destroying any evidence that Dib collects and he does need to deal with Dib as a near permanent threat, but he ended up getting past the point where any non-defective invader would have failed.

Also earth’s harsh environment would have caught any invader off guard, and there’s no way they’d use filthy earth paste as waterproofing, or even discover that paste can work as waterproofing in the first place because why would anyone look at primitive earth glue of all things as a potential solution to earth’s burning rain.

This is where Zim’s scientific background shines. He had a problem (earth’s water acts like acid), he found a potential solution (paste) and he tested it extensively until he found something that guarantees protection from water (the modified paste that Zim uses to waterproof himself). The scientific method in action.

Same goes for germs. While it’s unlikely that earth germs and sicknesses that effect humans could ever effect an irken, since they’re a completely different species with completely different biology, Zim realized that stuff like earth grease and meat could effect his biology, so why can’t earth germs and illnesses? Plus he found a potential solution (MacMeatys meat patties), tested it (meat suit), modified it after the first test was a partial success and kept testing and modifying until he got a permanent solution (I headcanon that he eventually found a way to mix his germ killing mixture and his waterproofing paste into one skin cream-like mixture that protects him from water and germs simultaneously). Any other irken would have just ignored something like that, which could end up either being perfectly fine or a fatal mistake.