The Nasat are a sapient species of crustaceanoid creatures known for their naturally cautious nature.
They are native to the eponymous planet Nasat, a heavily forested world which is also home to a sapient plant-based species known as the Citoac. As of the 24th century, they are members of the United Federation of Planets, but very few individuals are ever seen off-planet, due to their natural cowardice and shyness.
They physically resemble Earth isopods, with an average four feet height and varying skin color, which can be green, blue, red, brown or yellow. Their individual names consist of a letter, a number and the color of their skin (ex: M3 Green, P8 Blue, etc...).
Nasat have eight limbs, but are able to walk as easily on bipedal posture as on octopedal. The first pair of limbs is often used as manipulators, but the second and third pair can also exert that function. In some individuals, the arms end in pincer-like hands. Others appear to possess more humanoid hands.
Nasat have a broad head, with no visible neck, sporting a wide mouth, a pair of large pupil-less eyes. and in at least some cases a pair of antennae which are used as keen sensory organs, suitable for finding one's way around in a dark environment. In some individuals there seems to be a lack of antennae, although it is also feasible to suppose that the antennae might be retractable. They also make heavy use of the antennae for social gestures.
Like a pillbug, the Nasat are able to curl into a ball, protecting themselves with their chorion carapace. They are also able to move the exoskeletal plates and actively roll out of danger at high speed while curled up. The Nasat exoskeleton is extremely resilient, and allows them to survive in extreme environments including abyssal oceanic depths, the surface of a Venus-like planet, and even the vacuum of space for some time. It also makes them resistant to energy weapons.
Nasat build their cities among the forest canopy and coexist peacefully with the natural fauna and flora. They have no traditional concept of romantic or familial bond, and the larvae are cared after in nurseries. Like the Noophians, the Nasat have little regard for their own history, and place no historical or symbolic significance in old constructions, or even old documents and communal stories. There are no museums, no monuments and no preservation of history on the Nasat homeworld.
The Nasat ancestors evolved on the ground, where they were susceptible to all kinds of predators and other threats. They soon started to colonize the trees, building their settlements at increasingly higher levels of the canopy. They shared their world with a sapient but non-technological species of telepathic plants, the Citoac; and the two races often found themselves in active war against each other. Eventually, a treaty was established in which the Nasat would have control over the treetops and the Citoac would remain on the ground, as long as the Nasat agreed to build their cities in a way as to preserve the forest and not obstruct light from reaching the lower levels, since the Citoac rely on photosynthesis for nourishment.
Some Nasat are born with a condition which makes them almost unable to communicate verbally, but able to communicate telepathically with the plant-like Citoac. Known as Quiets, these Nasat have been historically pivotal in facilitating communication between the two races. For many centuries, there have been peace. However, because they lack the habit of preserving their history, the Nasat eventually forgot all about the Citoac and their treaty, and the Quiets were regarded as cripples and outcasts.
In the late 24th century, after the Nasat joined the Federation, they started several projects to expand their cities and install safety nets to prevent citizens and objects falling to the ground. These actions inadvertently infuriated the Citoac, who believed the treaty had been consciously broken, and started to sabotage the Nasat's constructions. Fortunately, a former Quiet named P8 Blue which had learned to communicate verbally thanks to the efforts of telepathic doctors Zoeannah and Tarak (a Betazoid and a Vulcan, respectively), was able to speak to the Citoac and clarify the issues. After that, the Nasat restructured the city in a way to no longer interfere with the Citoac's supply of light.
Behind the scenes
The name and virtually all information about this species comes from the Star Trek: Starfleet Corps of Engineers series of e-books, which although official and authorized, is not officially considered part of Star Trek canon. The only canonical appearance of a Nasat occurred in the animated series episode "The Jihad", in which we meet M3 Green.