The Control Brains are the overarching antagonists of the Nickelodeon animated series, Invader Zim and supporting antagonists in its Netflix film continuation, Invader Zim: Enter the Florpus.

They are large, computerized, brain-like creatures created by the Irkens for making both tough and basic decisions. They play the roles of the true leaders of the Irken Empire, and are responsible for making decisions in judiciary matters.

Among other purposes, the Control Brains would have conducted trials (also known as Existence Evaluations) of Irken criminals, serving as judge, jury, and executioner. Should an Irken fail their Evaluation, the Brains will eliminate them and erase their PAK's data so that it may never be used again to corrupt another Irken.

This would have ensured that the memories of the failed Irken don't get passed along to the Brains' hive mind. However, as the episode in which this would have been shown was cancelled before it could be completed, its canonical status is put into question whether or not it’s part of the show’s continuity.

It's also implied that the Brains are actually enormous supercomputers and, like all machines, they can malfunction and break down. If so, then a group of scientists and mechanics is often called in to ensure that the computers are at optimum efficiency. They also decide on elite soldiers' tests, determining whether the subjects pass or fail based on their performance ("Tak: The Hideous New Girl"). They can also reprogram an Irken's PAK and change their job and position, as seen in "The Frycook What Came from All That Space" and Enter the Florpus.

Control Brains appear to have been in line for a makeover, not unlike the one the Almighty Tallest went through mid-season. The concept art (see picture) for their appearance in "The Trial" makes them appear much more sinister, and more similar in appearance to a human brain. This redesign could be the true appearance of the Brains, as the ones that appeared throughout the series were wrapped in a metal casing.

Because of this, there are no visible gender differences between Brains, although a masculine voice was heard from one in "The Frycook What Came from All That Space", whereas Tak referred to the Brain that tested her as a "she".

In Invader Zim: Enter the Florpus, the Control Brains are no longer colored purple, magenta, or green, and instead are dark and ominous but their "eyes" seen to glow, unlike their previous incarnations on the show.

However, as their only appearance in the movie is Zim's daydream, it's unknown if this is what they really look like, or how Zim remembers what they look like as he has been far away from Irk and may be unaware of possible technological upgrades on his home planet.

It’s also possible that the coloration was meant to be taken as a representation of how bleak Zim considered his future at the hands of the Control Brains, who undoubtedly wouldn’t show him mercy for forgetting “Phase 2” of his plan.

Control Brains run the empire and their conclusions even have to be accepted by the Tallest, which means that the Tallest have no real authority over the people of Irk, and are simply figureheads (not unlike a constitutional monarchy).

Facts of Doom

• Control Brains have only appeared in "The Frycook What Came from All That Space", "Tak: The Hideous New Girl", and finally Enter the Florpus. More would have appeared in the unfinished episode "The Trial".
• Despite the six years run of the Invader Zim comics, the Control Brains never made an appearance.
• As the true leaders of the Irken Empire, they count as the true overarching antagonists of the Invader Zim franchise, as even the Almighty Tallest are figureheads for them.
• Earlier versions of Control Brains resemble very large PAKs. This may be where PAKs got their design, or vice-versa.

• In "Tak: The Hideous New Girl", during Tak's flashback showing her pleading with the Control Brain, some clips of "The Nightmare Begins" can be seen on the small screen on the Control Brain, hinting they could be capable of foreseeing the future.
• It's possible that there are Control Brains on planets that have been conquered by the Irken Empire.
• Jhonen Vasquez stated in the DVD commentary that Control Brains are actually genetically-engineered Irkens, heavily altered to the point where they no longer require bodies.
• It's possible that the Control Brains rule the entire empire, while the Tallest rule only Irk. However, this is never outright stated.
• Interestingly, the Control Brains can re-encode Zim's PAK from an Irken Invader to a Fast Food Drone without any problems. But, when they try to erase the PAK they turn insane.
• The Control Brains are based on the Supreme Intelligence from Marvel Comics.
• Jhonen Vasquez is credited as a "Control Brain" in each issue of the comic series.

• Oddly, in Enter the Florpus, the Control Brains act submissive to the Tallest rather than the other way around (similar to what is described above). But as their only appearance in the movie is in Zim's imagination, it's possible that this is merely him misinterpreting the power relationship between the Tallest and the Brains as Zim has a terrible track record with getting facts right.
  • Zim could’ve also thought that despite the Control Brains holding all the real power, they still had to show respect towards the Tallest to keep up appearances, similarly to how he shows respect towards his leaders despite the fact that he considers himself to be the most amazing Irken alive.
  • It's also possible that Zim has such a high respect for the Tallest that he may find it ridiculous that his leaders could be subservient to the Control Brains.
  • It's also possible that since "The Trial" was never produced, technically their position as superior to the Tallest was never explicitly canonically confirmed (despite some hints throughout some episodes being given), so it is possible that Jhonen Vasquez could have re-imagined how he pictured them and made that canon instead.

References

Irken Jobs
Advisor • Almighty Tallest • Control Brain • Irken Elite • Fast Food Drone • Frylord • Irken Invader • Janitor • Navigator • Service Drone • Soldier