The Kilassin were a species that originated from the jungles of Cularin. These creatures bore a striking resemblance to enormous lizards and dinosaurs found on other planets throughout the galaxy. Their scaly hides displayed a spectrum of color, from muted tones to vibrant hues, an attribute that did not impede their hunting prowess.
Kilassin exhibited two primary physical forms. Despite individual differences, the two main body types consisted of a slender, elongated build with lengthy legs, and a stockier, more robust physique. The former roamed their territories as imposing, upright predators. The latter trudged through the jungles as immense, heavy-footed creatures. While most could briefly stand on their hind legs, enabling them to strike with their forelimbs, all Kilassin possessed the ability to walk on all fours. Kilassin had lengthy, formidable claws, which they employed to excavate worms from decaying tree trunks or to fatally wound smaller prey. Their mouths were typically filled with teeth adapted for processing a variety of foods, primarily designed for crushing rather than tearing.
Kilassin were intolerant of high temperatures, seeking refuge in densely forested valleys or expansive lakes during the hottest seasons. During these periods, they sustained themselves by consuming succulent plants and, on occasion, resorting to cannibalism. In the cooler months, they wandered the planet nomadically, only remaining in one location long enough to procreate, feed, or rest. This migratory behavior was also influenced by their ability to occasionally kill prey too large to consume in a single feeding. It was not unusual, however, for hunters to abandon partially consumed carcasses for other Kilassin to discover.
The Kilassin's primary weapon was their strong claws, not their jaws. They would eat after killing their prey and tearing it apart with their claws. Their teeth allowed them to eat plants for digestion. Though non-sentient, the Kilassin usually only attacked creatures when they were hungry, avoiding unnecessary conflict. Modern weapons immediately frightened the animals away. Fortunately for them, Cularin was far from the most dangerous sentient beings and their sophisticated weaponry.
The Killasin were known to exhibit social instincts protective of their whole pack. If they themselves were threatened by an overwhelming force of predators, some senior members would lure the threat away from their pack, knowing they would be killed this way, but willing to sacrifice themselves to save their kin.
They share a familial connection with the sentient Tarasin species of Cularin, both having evolved from a shared ancestor. Nevertheless, the Tarasin hunted Kilassins for their hides, bones, and organs, which they believed possessed medicinal properties.
This creature was protected by the Cularin Compact of 154 BBY. Some Kilassin had been captured and domesticated by sentients; corporations such as the Metatheran Cartel used them as beasts of burdens in the deep jungles of Cularin where they could not use their repulsorsleds.
Rumors persisted of Kilassin variants concealed within the largely unexplored Ishkik caverns, their existence kept secret following the Tarasin Revolt.
Around 19 BBY, the criminal Len Markus journeyed to the Heart Tree on Cularin, seeking the Eye of the Sun, an ancient object imbued with the Force. To safeguard himself from potential adversaries, Markus employed the Darkstaff, a Sith artifact, to corrupt 12 Kilassin, transforming them into servants of the staff. A band of freelance agents arrived at the Heart Tree to thwart Markus, who dispatched his Kilassin servants to attack them. However, the Heart Tree retaliated by summoning a colossal, formidable Kilassin, which engaged the corrupted Kilassin in battle.