The Qohathoth were a spacefaring people that lived in our section of the galaxy approximately three million years ago. They all vanished 2.5 million years ago. Their homeworld has not been found.

Qohathoth science seems to have been mostly based around sound, using controlled vibration rates to transmute matter.

The Qohathoth spoken language is incredibly complex, combining sound and tone, and requires at least three sets of vocal chords to speak.

The written language is far simplified, but still confusing to a human reader. There are only thirteen 'letters', but each letter has between eight and twenty-six chord variations. Qohathoth writing also includes tonal glyphs to express the emotion behind the words. This is similar to entomorph tone-setting, though the languages aren't related.

The appearance of the Qohathoth is mostly based on guesses - the Qohathoth had a taboo about representations of themselves. Pieced together from their writing, it is known that the Qohathoth were in the area of 2.5 metres tall, had four arms, and it is inferred they had four fingers per hand since they used a base sixteen counting system. They may or may not have had wings - the writings seem contradictory.

Qohathoth Worlds
The most important thing the Qohathoth did for humankind was a campaign of terraforming. Natural worlds that can support human life are vanishingly rare. Qohathoth worlds are slightly more common - the estimation is that within the five hundred light-years humans have ranged, there are between four and five hundred terraformed worlds.

Since there is no evidence of the Qohathoth colonising the worlds they created, there is a theory that they couldn't survive on Earth-type worlds.

Qohathoth monuments are steles of various sizes made out of a brass-coloured, nigh-indestructible metal. Their purpose is communication.

All monuments have inscriptions on them, ranging from simple greetings to sagas. There is a way to get the monuments to play an audio recording of the inscription.

The most detailed monument is the one on Mars. In addition to greetings, it contains every trick the Qohathoth could think of so that humans could translate it once discovered. After it was discovered, it sent out a powerful signal. It wasn't until humans began colonising the galaxy that it was realised that the signal activated the monuments on the terraformed worlds, making them easier to find.

Monuments on terraformed worlds tend to have nothing more inscribed on them than greetings and the date the planet was finished. They give off short-range ( detectable within a solar system but little farther ) signals, making them easier to find.

The monument on Our Green Lady includes a sample of Qohathoth graffiti - the words My name is Kallomi. Remember me. are written on the back.

The Qohathoth/Yogzarthu War
Unfortunately, the Yogzarthu may have never even known about our universe if the Qohathoth hadn't contacted them long ago in their search to find intelligent life. The Yogzarthu tried to wipe them out, but the Qohathoth sealed them back in their universe and left the Dead Zone Monument as a warning.

The entire species seems to have vanished 2.5 million years ago. There are dozens of theories as to where they went. The most common ones include:

- Continuing their search to find intelligent life, the Qohathoth left en masse for another galaxy.

- Continuing their search to find intelligent life, the Qohathoth used their science to translate themselves to another plane of existence.

- Feeling guilty over their war with the Yogzarthu, the Qohathoth let themselves die out.

- The race merely came to a natural end.

Qohathoth Worship
The Listeners are a small human cult that worships the Qohathoth as agents of creation. They are easily identified by their robes, which cover everything but the eyes. Despite the name, Listeners travel to visit monument sites and sing to them. They worship in groups of three or more to better duplicate Qohathoth voices.

Though the entomorphs understand that they would not have developed had the Qohathoth not terraformed Tethys and they are pleased that they exist, the entomorphs don't hold any particular reverance for the Qohathoth.

The Listeners are divided on whether the entomorphs get special holy status as a product of Qohathoth work or if they're ungrateful blasphemers for not worshipping the Qohathoth.