The Nameless
A group of fungal entities that sustain themselves by consuming concepts and ideas, effectively removing those concepts and ideas from the thoughts and memories of people around them.
The strongest of these creatures can wipe a concept from the minds of an entire nation, or even an entire world. Usually they need to enter a position of authoritarian power to do this without their nature being revealed.
The Nameless unanimously agreed not to be found or identified by other entities, so as not to be hindered in their feeding. People who hear of them tend to forget nearly immediately, and the Nameless have protocols in place to delete/destroy any written documentation of their existence.
Many of them parasitize an individual human, prioritizing the elderly, due to their abundance of knowledge and general inability to resist. The Nameless tend to occupy senior citizen homes.
Sometimes, however, they choose to parasitize younger humans that are sickly but book-smart. While also unable to resist well, and too young to have gathered an abundance of knowledge, they tend to pick it up quickly and make sufficient hosts for the Nameless.
Spanning across multiple galaxies, The Nameless have learned that intelligent and social species make the best hosts, and make a point not to feed on knowledge that would otherwise lead to the invention of global communications.
Nearly every planet occupied by the Nameless has the following traits:
- Primarily inhabited by an intelligent and social species that is capable of developing civilization.
- The primary species is NOT a hive-mind species. The Nameless can't feed on hive-minds.
- Some form of long-range communication is developed within a few years of colonization.
- Global communication is achieved in around a century.
- Despite unhindered access to information, the primary species seems too unintelligent to have invented their communications in the first place. This is due to late-stage feeding.
- Always on the tipping point of annihilation; the Nameless need to cover their tracks so as not to be caught.
- Even fictional references to beings similar to The Nameless are wiped or drowned out by unrelated information.
- The primary species is deliberately drip-fed incorrect information about the nature of the universe. Some of this false information is benign, other false information is intentionally designed to draw the species off the scent of the Nameless.
- The benign false info serves as both a red herring and a point of argumentation between members of the primary species, to distract them from discovery.
- For example, humans were led to believe that the electrical signals between neurons were the source of their sapience and not a side effect; while the nature of butterflies, a species that dissolves down to the neuron but can remember stimuli from before pupation, disproves this belief in its entirety, research on why this is the case has been deliberately stunted.
- The few researchers who discover the real reason are fed on, and the explanation is lost.
- They've caught me.
As I mentioned, in this fictional version of Earth, they're fungal. Their form is a spongey mycelium-like structure that is nearly indistinguishable from human nervous systems. Most doctors would never consider them something wrong, as they see this in nearly everyone, and it's listed as a "normal variation in anatomy" in all textbooks.
In the world I'm building, humans would not have existed without the Nameless, and are quite literally domestic livestock who don't even know they're being fed on. The reason (in this fiction) that animals are more closely related to fungi than plants is literally because they were engineered to be compatible by final-stage hosts of another planet, that were destroyed after use.
They can't live without a host, as they feast on the information that the host learns. In later stages, the host will "autopilot" quite a bit, responding as if they heard what they were told without actually processing anything. This is because their nervous system was literally hijacked.
Hungrier Nameless will often consume information as soon as the host learns it, causing problematic memory loss.
Infection usually has to wait until the brain is somewhat close to done with development, as early infection may result in the brain not being suitable to learning enough to feed the Nameless strain they are hosting. Desperate nameless strains will sometimes try to infect infants, but they die when this happens.
I realize I wasn't clear with my wording here--a single "strain" of Nameless is an individual infecting one or more hosts, and can communicate similarly to a hive mind, but is isolated to its own strain. If a strain infects an actual hive mind, then the Nameless strain and the hivemind can actually communicate with each other via abstract processing.
That, and to clarify another comment, infected infants die, not the strain trying to infect them.