Agarthans are a species of subterranean-dwelling hexapodal vertebrates with the foremost and hindmost limbs being primarily used for locomotion while the mid-limbs are significantly smaller and used primarily for grasping and fine motor manipulation; while it is possible for an Argathan to rear-up onto their hind legs, its actually extremely difficult and even the most athletic can only hold this upright posture for a limited time before it becomes painful to maintain. The foremost limbs are notably large with denser bones and musculature along with massive claws which they use to dig through densely packed soil and rock to expand their underground warrens, the excavated material being used to subdivide the space into rooms and levels for private dwellings and public spaces. typically Agarthans will average between 6’-7’ in length from nose to haunch though allegedly some members of the species have been reported to get as long as 20’ in length with skin tones ranging from black and grey to white with bioluminescent patterns running along their back and sides. They also have long, fleshy stalks sprouting along their backs and brows which also end in bioluminescent bulbs which emit enough light to illuminate their surroundings, the color of Agarthan’s bioluminescence being either blue among men and yellow or white among women. The head of an Agarthan is on the end of a long, flexible neck and has a prominent snout with what initially would appear to be six nostrils but only the foremost two are for the actual nose and the other four being heat-sensitive organs. Their mouths have an outer row of long, hook-like teeth and an inner row of blade-like incisors and few underdeveloped molars, which is indicative of their diet which is almost entirely comprised of meat and occasionally supplemented with roots and fungi. Agarthan hearing is actually rather underdeveloped and is slightly worse than human hearing. Their sense of vision is also rather unimpressive overall, as while it is true that they can see in very low light conditions, nearly all Agarthans are nearsighted and have red/green color blindness.

Not a lot is known about Agarthan history, or more accurately, there’s not a lot known about Agarthan history that isn’t demonstrably false. They claim to be native to Earth, despite having multiple genetic markers not native to the Sol system, and no evolutionary ties to any Earth-native species. They claim that their civilizations have a history going back 250,000 years (conveniently making their civilizations 50,000 years older than anatomically modern humans at the time of their claim) despite there being no archaeological proof of any Agarthan presence in the whole of the Sol system prior to [1200 B.C.]. They have also claimed that they originated from the lost continents of Atlantis and Lemuria, both of which are fictional lands invented by humans, something one would think a species claiming to have a recorded history going back farther than human existence would know.

What is known for certain is that the Agarthans are an extraterrestrial species that likely settled on Earth roughly 3200 years ago though from where exactly is still a mystery. Today The largest concentrations of Agarthan warrens reside under the Cascade, Himalayan, and Transantarctic mountain ranges; each region having its own unique cultural, architectural, and linguistic characteristics and effectively function as autonomous nation-states, though the Agarthans are hesitant to call them as such themselves.

It should also be noted that while the Agarthans have access to interstellar travel, they have curiously made no serious attempt to colonize any other worlds besides Earth for reasons largely unknown to the wider interstellar community