Invader Zim Analysis: What's the deal with SIR Units?
Y’know, the SIR units in “Invader Zim” have always fascinated me, even though the show doesn’t feature them much except for GIR. I feel like I don’t see many people in the fandom talk about them much, so I figure I’d take this opportunity to throw in my own two cents about these little guys. As a quick memory jogger in case you forgot what the SIR units purpose in the Irken Empire is, they’re small Irken-built androids that are only assigned to high-ranking Irken invaders. They act as robotic assistants who aid their masters in gathering weaknesses on the planet they’ve been assigned to invade and double as bodyguards who eliminate any threats to their masters. Also, as a random side note, according to Almighty Tallest Red, they apparently double as thermoses for some reason.
Given that a bloodthirsty imperialist race built them, it’s not surprising that SIR units store deadly state-of-the-art weaponry, such as lasers, missiles, saws, and bombs, all in their heads. Despite looking like tiny and weak-looking robots, they’re deceptively durable and powerful. If an older model like GIR is any sign, they can easily lift thousands of tons, even with its noodle-looking arms. They also possess the ability to move at high speeds.
Now, a detail I find funny is the possibility that the only reason the SIR units are built as small as they are is because of the Irkens’ obsession with height. The Almighty Tallest obviously wouldn’t want their invaders to boss around a robot servant that appears to be taller than them because that would set a bad precedent. One could make the argument that it’s also because the SIR unit’s small size means that it could hide and gather information more easily, but knowing how the Irken Empire runs, it’s most likely the former reason. That being said, another advantage of the SIR units’ appearance is that an enemy encountering them for the first time wouldn’t realize just how truly dangerous the SIR units are before it’s too late.
Now, if you recall, I mentioned earlier that the Irken invaders are the only ones granted access to SIR units, but it’s implied they don’t keep them after finishing their missions. For example, in the episode “Battle of the Planets,” Invader Skoodge is the first invader to complete his mission of conquering his assigned planet. Interestingly, when he presents himself to the Almighty Tallests, he doesn’t have his SIR unit by his side. In fact, we never actually see him with his SIR unit on screen at any point, but we know he had one thanks to promotional material. Anyway, it’s likely that any invader who completes their assigned mission gives up their SIR unit so that it can assist another invader in the future with the data it collected during its time with its current master. This lends credence to the idea that most invaders don’t really get very attached to their SIR units, just viewing them as expendable pieces of technology, especially given what we see in the episode “Megadoomer” which I’ll elaborate on later. The closest the Irkens get to humanizing them in any way is giving them nicknames and giving them male/female pronouns; however, only Tak has done this, naming her SIR unit MiMi.
It’s possible that Zim and Tak are the only non-invaders who not only own a SIR unit but also have full ownership over their SIR units instead of the Irken Empire because of the unusual circumstances of their robots’ creations. The Almighty Tallest built GIR to fool Zim into thinking his mission was real with the added belief that GIR was a top-secret model. It’s unlikely that even if Zim completed his “mission,” he would have to give up GIR because he’s a broken and outdated SIR unit and the Almighty Tallest would rather have GIR continue to be a hindrance to Zim. As for Tak’s SIR unit, MiMi, it’s heavily implied that Tak created MiMi (along with her ship) from scrap and other useful materials during her time on Planet Dirt. This would explain why MiMi has such a drastically different appearance to the other SIR units. For instance, she has the same outdated chest plate GIR has, but also has a mouthless head similar to the modern SIR units, with her most stand out feature being her giant extendable claw. MiMi, simply put, is not like any of the other modern SIR units despite being just as advanced, but she wouldn’t fit in with the Irken Empire’s pre-existing SIR units lineup at all.
Well, I’ve rambled enough about the SIR units’ role and treatment in Irken society, but something else I wanted to cover was the shoddy and questionable programming of the SIR units themselves. While we know nothing about who specifically created the SIR units or how long they’ve been in production in the Irken Empire, we at least know who programmed them. An Irken scientist named Hok designed the original programming of the SIR units, as revealed in Issue #23 of the Oni comics. Hok also uploaded a digital brain-scan version of himself into the SIR units that acts as an error-correcting software, but its effectiveness is very questionable as you’ll see later on.
So remember earlier how earlier I brought up how the Irkens only see the SIR units as expendable pieces of technology? Well, that’s because of how we see how they deal with broken SIR units in the episode “Megadoomer” or lack thereof. At the beginning of the episode, we see the Almighty Tallests at a storage planet doing an inventory check on the titular Megadoomer to give as a gift to Invader Tenn in aiding her conquest against Planet Meekrob. And a few floors above the Megadoomer is a bunch of malfunctioning SIR units attacking each other. The Tallest's nonchalant reaction to them gives off the idea that malfunctioning SIR units are a fairly common problem in the Irken Empire. They aren’t interested in getting them fixed and instead decide to have them sent to Zim hoping they’ll kill him. This can be yet again chalked up to the laziness and apathy of the Almighty Tallest not wanting to fix them. Granted, what we see of these broken SIR units is that they are incredibly dangerous, so maybe getting them fixed isn’t worth the trouble.
Anyway’s if you remember how the rest of the episode goes, a rogue slave switches Zim and Tenn’s packages at a planet shipping facility. This leads to Zim getting the Megadoomer (which has its own set of problems) and Tenn getting the deadly package of SIR units, which ends up destroying her base. While it’s an enjoyable and funny episode to watch along with Zim’s little lore drop about the Vortians being recently enslaved, the malfunctioning SIR units especially fascinated me. When we first see them on screen, you might think their actions are like how GIR normally acts. However, they are a lot more destructive than GIR is, and they have no agency over what they do at all. Yes, GIR has had a few destructive moments, with the most notable examples being “Invasion of the Idiot Dog Brain” and “GIR Goes Crazy and Stuff”, but in both instances there was at least a reason for it. In the former episode, GIR’s rampage when he became the base’s computer was because he wanted tacos, and the library rampage in the latter episode happened because he was trying to destroy Zim for his incompetence. The malfunctioning SIR units, on the other hand, have no autonomy over what they do, but I might have an explanation for them attacking each other.
In the previous paragraph I mentioned the episode “GIR Goes Crazy and Stuff”. In this episode, Zim tires of GIR’s goofiness and stupidity and locks him into duty mode so he’ll be an effective servant. At one point in the episode, GIR in his serious state brings up an Irken law called the SIR unit code. This law allows SIR units to act of their own free will if they and their master’s mission are under threat. One example we get of this behavior in a fully functioning SIR unit is MiMi destroying Zim’s base in “Tak: The Hideous New Girl” without Tak ordering her to do so.
However, GIR is an example of a SIR unit who almost never functions properly at all, but is still aware of the SIR unit code to begin with. A lot of GIR’s goofy moments in his malfunctioned state make a lot more sense with this information. To put this into perspective, as long as Zim is around, the mission is always at stake, and therefore, GIR will always have his SIR unit code enabled to do whatever he wants. Only after GIR was locked into duty mode for a long time did he become more acutely aware of the SIR unit code’s true purpose, which is why he also tried to wipe out Zim the moment he got the chance.
I bring this all up to say that the SIR unit code itself is likely the culprit for causing the malfunctioning SIR units. The SIR units in “Megadoomer” were all likely in a situation that granted them temporary free will, but some sort of glitch could’ve caused them to stay in that state of free will that Hok’s self-correcting program could not fix. Also, since these SIR units are implied to be newer models (GIR and Mimi have older parts), it’s possible they still don’t really understand this code and, by extension, their free will like GIR does. By the time the Invader figures out their SIR unit is malfunctioning by it not responding to commands correctly or worst trying to attack them directly they’ll have already had it sent back to the Irken Empire to have them stored away assuming they haven’t gotten severely injured or killed by it.
GIR’s understanding of his free will even in his malfunctioned state is thanks to his circumstance of creation being different compared to the other SIR units. There’s also the fact that while on Earth he’s learned a bunch of fun skills just by watching TV, since that’s where he gets his information from. That’s why he’s able to do many things like cook, socialize with humans, and eat even if he can’t digest food. In a way, he’s still gathering information like a normal SIR unit, but none of it is useful information to his master’s mission. He watches what he wants because of his free will.
However, when you compare that to the standard SIR units, they don’t have this frame of reference because their purpose was solely for combat and scouting. It makes sense that their first act of free will would be to test their weapons. After all, what would a robot built for espionage and combat really know or do with its newly gained sentience? However, another explanation for the SIR units attacking each other in “Megadoomer” is that their “mission being under threat” protocol is still active, even in their malfunctioned state. That could be why they’re all fighting each other: they all think of one another as a threat to their masters and their missions, even if none of them have masters anymore.
With all this said and done, I honestly think it’s impressive and kind of wholesome that Zim’s kept GIR with him for so long, even if it’s only because the Tallest lied to Zim about GIR being a “top secret model”. When I said that Irken Invaders treat SIR units like expendable pieces of technology, I meant it. Even Tak had no problem dismantling MiMi when GIR took control of her in “Tak: The Hideous New Girl” and started destroying her ship. True, MiMi was an active threat to Tak even if she wasn’t really herself, but Tak didn’t care about MiMi after disassembling her. Zim has never once tried getting rid of or destroying GIR, even when GIR attacked him in “GIR Goes Crazy and Stuff”. Given Zim’s affinity for robots (which is a discussion for another time) he treats GIR more like a sibling than a servant, which is definitely something the other invaders would never do with their own SIR units. You could say that it’s a good thing that Zim got GIR instead of a regular SIR unit because he likely wouldn’t have a good relationship with it.
If you made it all the way to the end of this gigantic post, then I can’t possibly thank you enough for taking time out of your day to read this. I can only assume you're as much of an Invader Zim mega-fan as I am to search out and read about minor background characters for a cartoon that’s no longer airing or producing anymore comics. I should mention I’ve never written an analysis on Tumblr before, so I’m sorry if it’s kind of wordy. I’m actually not sure if anyone will even read this, but honestly I had a lot of fun just writing and researching. Regardless anyone reads this or not then I’m happy I could give my personal thoughts on a topic I thought was fun to discuss. I got a lot of inspiration to write this analysis from other Invader Zim posts I saw on this site alongside some non-Invader Zim analyses of other media I love. I’m not sure if I’ll ever write another analysis post like this, but with how much fun I had, who knows? Maybe I’ll make another one Invader Zim related or not. The only other similar type of piece I’ve written was on the dragons from G4 My Little Pony that I wrote a few years ago that I never really shared anywhere. Who knows, maybe I’ll share that one too when I go back and re-read it.
I should mention before closing out that some of my points in the later sections of my analysis actually come from my reply to a YouTube comment on the “Malfunctioning SIR Units” video that brought up this neat little idea:
I thought it was pretty interesting, so I wanted to give my own thoughts on it that were far longer than the initial comment. And many months later that led to me wanting to go even more in-depth which resulted in this posts creation. So big thanks to that random YouTuber's comment for this post even existing in the first place.
