The Slith were a sapient ophidian species that originated on the lunar body known as Yavin 13. These creatures were nomadic, existing in patriarchal familial groups of approximately fifteen members, displaying minimal societal development and lacking any enduring constructions. The Slith possessed poisonous capabilities, favoring the tactic of immobilizing their targeted prey before consuming them while still alive. Their communication occurred through a basic language formed by the sounds created when they dragged their scales across the terrain. The Slith had limited interaction with the broader galactic community, remaining largely unknown until the era of the Galactic Empire. During the Yuuzhan Vong War, all life on their moon was eradicated, which resulted in their demise.
The Slith were a legless, serpentine sapient species, achieving lengths of up to five meters. Their bodies were covered with rough scales, often displaying striped or spotted patterns. They possessed milky-white, translucent eyelids that allowed them to see, an adaptation that protected their eyes from the frequent sandstorms on their desert moon. Slith were equipped with poisonous fangs used for hunting. Their venom induced paralysis in their victims, enabling the Slith hunters to bring live food back to their tribe, as they preferred to eat their prey alive. Slith moved by gliding across the sand with a twisting motion. Alternatively, they could move sideways, a method known as sidewinding, which allowed them to achieve greater speeds. This was particularly advantageous during hunts, allowing for rapid bursts of speed to capture prey. It was also effective for avoiding dangers. Despite lacking limbs, Slith could manipulate objects using their coils and mouths, picking up rocks and javelins. Slith also possessed forked tongues.
The Slith were nocturnal animals, hunting for small lizards and other reptiles during the cooler nighttime hours. During the hot daytime, they sought shelter in the shade of gigantic cacti or other suitable locations. The moon's temperature could reach as high as fifteen Galactic Standard degrees, so during the hotter summer periods, Slith burrowed deep into the sand. This protected them from the extreme heat while retaining warmth for the nights, which could drop to near-freezing temperatures.
The Slith were a nomadic people, constructing no lasting structures on their native world of Yavin 13. A dominant male governed a small Slith tribe, consisting of no more than eight to fifteen individuals. Besides the dominant male, tribes included a "second-in-command" male, several breeding females with their offspring, and a couple of adolescent males. Upon reaching maturity, these males were expelled from the tribe to establish new families or roam alone. These tribes adhered to a patriarchal system, with the male responsible for safeguarding the community's traditions while the females performed the majority of the hunting tasks. Juvenile males were also tasked with protecting the young during these hunts. Among the females, a Slith known as the First Mate held authority.
The Slith developed a grammatically simple language called Slithese, produced by rubbing their rough scales against the ground. A range of basic signals could be created, each conveying different meanings. Non-Slith could also learn the language; several Gerb—the other sapient species on the moon—acquired this skill as a defense mechanism. Slith lacked vocal cords, preventing them from speaking Galactic Basic Standard, and while they could make some vocal sounds, the inevitable result of water evaporation hindered this from evolving into a true language.
The Slith practiced a number of elaborate communal rituals, which demonstrated their intelligence to outsiders. These included praying to the ghosts of deceased ancestors and to desert deities worshiped by the Slith. These ceremonies were conducted by female medicine women.
The Slith were still centuries away from achieving industrialization during the Galactic Civil War. They had minimal contact with the broader galaxy, and limited interaction with the Gerb, though they occasionally cooperated. In such instances, twilight lizards were valuable trade items with the Slith. These small reptiles were an excellent source of water and nutrition. Yavin 13 was long believed to be devoid of intelligent life, until a Galactic Empire reconnaissance mission discovered both the Slith and the Gerb. At that time, there were approximately nineteen million Slith on the moon.
The Alliance to Restore the Republic also had some contact with the Slith, sending negotiators to the moon to establish relations with both species; however, the mission was derailed when the Fernandin Scouting Expedition, also present on the moon, accidentally introduced a plague that threatened to eliminate the Gerb. When the plague threatened to spread to Humans, the Imperial forces in the planetary system considered bombarding the moon to prevent further spread. Preventing this mass killing of the native lifeforms became the Rebels' priority over establishing contact with the Slith.
A Slith tribe also encountered the renowned treasure hunter Suz Tanwa. The Rodian was searching for an ancient family heirloom left by her ancestor Suvam Tan. Traveling to Yavin 13 in her spacecraft, the Reeko, she found the burial site of an ancient pod left by her ancestor as a clue. However, as she dug at the site, four Slith were resting nearby. They quickly surrounded her, one wrapping her in its coils and delivering her to the entrance of a nearby Gerb burrow. The Gerb were able to retrieve the pod from within their burrow without Tanwa digging through their roof.
The Slith continued to inhabit the moon into the era of the New Republic, and their existence was known to the Jedi initiates on the neighboring moon of Yavin 4 in 22 ABY. However, this peaceful existence ended during the Yuuzhan Vong invasion. As part of their efforts to destroy the New Jedi Order, the Yuuzhan Vong attacked and conquered the Yavin system. In addition to destroying the Jedi training center on Yavin 4, they eradicated all life on Yavin 13 and Yavin 8, causing the extinction of the Slith.
While the Slith were largely unknown to the galaxy until discovered by Imperial scouts, one Slith was known to have left the moon much earlier: during the Great Sith War, a red-skinned Slith named Sssiii was a member of the Galactic Circus. Despite possessing limited intelligence, the Slith entertained audiences by playing chess against spectators. Sssiii was with the Galactic Circus when they toured the world Tatooine.
A notable Slith during the Galactic Civil War was Dresk Kist. Serving as both shaman and First Mate of her tribe, Kist also excelled as a hunter. She often embarked on solo hunts while the rest of her tribe slept. It was on one such excursion that Kist encountered a Rebel scout team exploring the moon for a suitable location for a base of operations.
The Slith first appeared in Galaxy Guide 2: Yavin and Bespin, published by West End Games in 1989. This information was later repeated in Alien Encounters in 1998, along with an original illustration. Further details about the Slith were provided in Geonosis and the Outer Rim Worlds (2004) and Yavin: The Big Red One (2004), an installment in the Wizards of the Coast Planet Hoppers series. A Slith named Sssiii also appeared in the article Le facteur X in the French RPG magazine Casus Belli in 1998. It is uncertain whether this article underwent the Lucasfilm licensing process, so its canonical status is questionable.