Data organism or data lifeform is a term used to describe humanoid interfaces and less-developed creatures seemingly created from data.
Mystérique Sign creatures
These creatures are distantly related to the Data Overmind, and are considered much more primitive from branching off in the distant past. It was believed to be extinct until the Mystérique Sign incident.
The creature cannot exist without using a human brain, and how it is perceived by others depends on the mind of the victim.
Approximately 280 million years ago, one became stranded on Earth. There was nothing like a computer system for it to possess, so it fell into hibernation until the appropriate infrastructure came about. When humans invented computers, it entered a half-awake state.
In Mystérique Sign, North High student Haruhi Suzumiya created a new symbol for the SOS Brigade website. Her powers fully awakened the data lifeform by unleashing a torrent of data, totaling approximately 436 terabytes of information. It became linked to the SOS Brigade website. Anyone who saw the website (outside of the energy-laden atmosphere of the SOS Brigade headquarters itself) would fall into an alternate dimension with properties similar to data jurisdiction and closed space. The creature propagated numerous links to the website, luring more people into the trap. Each would fall prey to a "clone" of the creature.
Humanoid interface Yuki Nagato noticed the problem and "crashed" the site. Meanwhile, she and fellow interface Emiri Kimidori drew Haruhi into investigating one of the missing victims, a student at North High—the Computer Research Society President.
The SOS Brigade entered the president's apartment. After Haruhi left, the rest of the Brigade entered the creature's space via Nagato's incantations and engaged it in combat. It was swiftly defeated.
Afterward, Nagato altered the SOS Brigade symbol so no one would be affected by the image. Itsuki Koizumi and Nagato pointed out that eight other people had fallen victim to the creatures, five of them North High students. Kyon resolved to help rescue them.
Manga: Mystérique Sign Returns
- Main article: Mystérique Sign Returns
One of the victims was Kyon's grandmother, who had visited the SOS Brigade website. Kyon went on a rescue mission, disguised as a family visit. He took his little sister with him, but only had indirect help from the SOS Brigade. Nagato gave him her glasses, which she had modified into a trap to destroy the creature.
Kyon, wearing Nagato's glasses, had to confront the creature in a well-lit location and stare directly at it, maximizing his visual "vulnerability" to lure it. Frightened, he called Nagato, who told him the task was "not hard". Unfortunately, Kyon had trouble, as the creature looked just like his grandfather when young (like Kyon, in fact) dressed in an Imperial Japanese Army uniform with a katana, advancing menacingly on him. Worse, his sister became interested in his activities and she showed up, unknowingly putting herself in danger. Kyon couldn't even look toward her, but shouted at her to leave. Left alone, the creature jumped at Kyon, but as it passed through the glasses it exploded, leaving behind a small smear.
Kyon's grandmother returned to existence, having thought she had merely fallen asleep.
In Wandering Shadow, a series of "paragenetic silicon-based data lifeforms" fell to Earth. They consisted of a symbiosis of silicon life which had reached an evolutionary dead end, unable to process thoughts other than those related to self-preservation, and data lifeforms, which were nothing more than isolated data clusters. In order to obtain new data, the data lifeforms would attach themselves to any suitable material, like the silicon lifeforms. "Both parties form a mutual interaction for their individual benefit."
The silicon creatures burned up, but the data organisms still existed. These "spirits" were discovered to be infesting dogs. More primitive than the Data Overmind, they cannot be perceived by normal humans.
They made the dogs sick, and in addition, the beings were now more limited than they had been in silicon bodies. In an effort to expand their memory circuits, they intended to infest other dogs.
Upon discovering them, Nagato determined the data compositions had to be subdued, then compressed into a small space and shut off. They could not simply be exterminated; the Data Overmind determined they were beneficial to the universe. She would need to prepare a new interface—Shamisen.
They agreed on the cat because the data lifeforms would not harm him. Nagato placed data parasites from a pair of ill dogs into Shamisen and froze them.
A month later, she asked Kyon if the cat was okay, and he said it was.