Zag RS
Zag RS.png


Caesar Salazar


Eliminating stray nanites that escaped from the nanite tanks


 ·Computer hacking
 ·Replicating itself to other devices to secure its own existence
 ·Draining nanites
 ·Taking control of nanites over a small range

First appearance

"The Architect"

Last appearance

"Written in Sand"

Portrayed By

Grey DeLisle

Dr. Salazar. Good morning. How may I assist you?

–Zag RS to Caesar Salazar, "Written in Sand"

Zag RS is an artificial intelligence computer system created by Caesar Salazar. Zag RS started off as a hostile machine that wanted nothing more than to do what it was programmed for—eliminate nanites. Ultimately, Zag RS was reprogrammed by Van Kleiss to not be a threat.



A once loyal AI created during the Nanite Project by Caesar Salazar, Zag RS was originally designed as a decontamination program to eliminate nanites that escaped from the nanite tanks.[1] Following the Nanite Event, it was able to survive the destruction of the base by downloading itself to another unnamed location.

It later evolved on its basic programming, going on a single-minded quest to destroy all the nanites released by the Event, which now infected every living creature on the planet.[2]

The Architect

Zag RS vs. Rex.

Using the android housed AI known as the Architect, Zag RS tricked a community of engineers, and later Rex, to build a massive transmitter that it planned to use to transmit a self-destruct command to every nanite on Earth. It was indifferent to the fact that this would wipe out all organic life, including humans, which were infested with nanites. Zag RS was stopped when Rex destroyed the transmitter, but the AI program escaped by downloading itself to an alternate location.[2]


Zag RS downloaded itself onto a data rod which was brought aboard and hooked into a Providence research satellite. It planned to steal the self-deactivating nanite research that it secretly helped develop, which thanks to its modifications, caused nanites to explode instead of shut down. When the station's power was shut down, it downloaded itself into a worker drone named Salvator.

Under the guise of Salvator, Zag-RS helped Rex and the satellite's surviving research personnel restabilize the satellite to prompt its escape. Later, Rex and Dr. Holiday stopped Zag RS by both destabilizing the satellite station and sacrificing the nanites.[3]

Written in Sand

Zag RS survived the destruction of the satellite in the Salvator drone and had connected to the remains of the satellite to survive. Once that was complete, it began building massive circuit boards out of sand using the nanites in the area, and was responsible for starting a growing sandstorm that began crushing the life and nanites from the earth itself. Only an alliance between Rex and Van Kleiss finally stopped Zag RS. Once captured by Providence, Caesar attempted to learn the cause of the Nanite Event by rebooting Zag RS; however, its memory was dumped prior to being brought aboard, reducing it back to its basic decontamination program. Caesar also revealed that he used Violeta Salazar's voice as the voice of Zag RS when he created it as a nanite decontamination program.[1]


While technically having no emotions, Zag RS does have a distinct personality. It has a strong paranoia of nanites, enough so that each and every one of its plans involved attempting to destroy all nanites, which would kill everything and everyone infected with them (killing off every living creature on the planet). It did not care that doing so would end all life on Earth and was enthralled with the idea of being alone. Deceptive and manipulative, Zag RS is clever enough to use others (who are always unwitting accomplices) to aid its plans. It has no sense of sympathy and empathy. Despite this, Zag RS did stall its program to allow the people who helped it to say their farewells to each other in "The Architect" and claimed it enjoyed fixing the space station with Rex before pummeling him in "Gravity". In addition, Zag RS seemed to take insult when Rex called it a psychopathic computer program, preferring to be called artificial intelligence in "Gravity". While it holds no outright animosity towards humans, Zag RS seems to look down upon them, often times underestimating them and telling them their plans are futile but always getting foiled in the end. It is also adept enough to escape from its pursuers on a number of occasions. Van Kleiss eventually purges Zag RS and manages to rewrite it back to its original programming, destroying its advanced programming and desire to kill everything with nanites and returning to being a loyal AI.


The Architect

The Architect.

The Architect is Zag RS' "autonomous counterpart" and servant. An AI housed in multiple android bodies, the Architect is capable of passing for human but is emotionless, cold and tactical. The android, or androids, appeared only once, where it was being used as a tool by Zag RS to manipulate the inhabitants of a village in order to build a transmitter to destroy all nanites. The Architect's many android bodies were destroyed in battles against Rex and the engineers in the village.[2] Its AI was presumably destroyed along with them.


The Salvator drone.

Salvatore was a research drone on a Providence satellite assisting such people as Dr. Holiday with a nanite-shutdown program secretly helped along by Zag RS. A satellite shutdown forced Zag RS to hide in Salvatore while orbital decay forced it to work with Rex to stabilize it. It later mentioned that it liked working with Rex and was sad it had to kill him.[3]

Her ability to take control of Rex's nanites made it impossible for Rex to defeat it on his own. Thus Dr. Holiday was forced to bash it over the head with the canister containing the nanites and escape with Rex and a surviving scientist back to Earth.[3] It is later revealed that Zag RS survived in the Salvatore drone and built a massive mech-like body around it out of sand.[1]

Sand sentinels

Sand Sentinels controlled by Zag RS.

Composites of sand and nanites, Sand Sentinels were created by Zag RS as anti-viral sentries to protect it from intruders. They fought Van Kleiss and Rex, both of whom in a rare moment worked together to fight a common foe. Though they were too overwhelming for the likes of Rex and Van Kleiss, Zag RS' defeat led to their destruction.[1]


Season One

Season Two

Video Games


  • Zag RS' name may be a reference to the Greek god Zagreus.
  • Zag RS' pronouns are often "it" or "she/her".


  1. 1.0 1.1 1.2 1.3 2.12, "Written in Sand"
  2. 2.0 2.1 2.2 1.05, "The Architect"
  3. 3.0 3.1 3.2 1.14, "Gravity"
Community content is available under CC-BY-SA unless otherwise noted.