By 18 BBY, a colony of netcasters had nested on Kashyyyk near a remote Wookiee village which had once been the home of the Jedi Gungi. Gungi—who had survived Order 66 and the initial stages of the Great Jedi Purge—returned to his homeworld with the assistance of Clone Force 99 in hopes of rediscovering his native village. As the group trekked through the Kashyyykian wilderness, they encountered the netcasters' dense webbing and began to slice through it; the arachnids promptly descended and confronted them but ultimately allowed the non-hostile intruders to proceed. Later, the same colony found their territory aflame when a conflict was ignited between Gungi's allies and an association of Trandoshans and Imperial troops. During the fight, the Trandoshans, who showed no similar amicability toward the creatures, provoked the wrath of the netcasters and were quickly overrun by their numbers. Meanwhile, the Trandoshan commander Babwa Venomor was captured, wrapped in silk, and lifted into their web for consumption.
Rear view of a netcaster
Netcasters were broadly arachnoid in appearance, possessing a yellow or golden spoon-shaped body which was wider at its lower extremity than at its uppermost. Darker, off-color stripes circumscribed its body horizontally. At the top of its body was a head, upon which sat six eyes arranged in two groups of three. A flower-shaped organ of six petals was affixed to its body immediately beneath the head. From its body protruded four long legs for locomotion, also yellow, which were composed of multiple segments. Each leg terminated in a set of claws surrounded by multiple petal-shaped flaps which could be opened to reveal the claws in an intimidating manner. Webbing was spun from an orifice at the arachnids' rear.
Netcasters were arboreal arachnids which inhabited massive webs they constructed amidst the towering planetary forest of Kashyyyk. They engaged in swarming behavior and were carnivorous predators, feeding on intruders ensnared in their sticky webs, including such species as the reptilian Trandoshans. To prepare it for consumption, netcasters cocooned their prey in websilk, which substance was also used to control their descent from the trees.
The creatures were territorial and fiercely protective of their habitat. When threatened, netcasters stood on three legs and flourished the remaining leg's claws at the offender. However, they were at least capable of drawing distinctions between hostile and non-hostile intruders; those deemed unthreatening were permitted to pass through unharmed, while those deemed belligerent to their interests were seized, wrapped in silk, and lifted into the webbing.
Netcasters were native to Kashyyyk and became a ubiquitous presence amongst the thick jungles of the planet. They wove nests across its immense trees and feasted on intruders ensnared in their thick webbing. The furry Wookiees, also indigenous to the planet, were familiar with the netcasters and aware of the species' territorial behavior. By 18 BBY, a group of netcasters colonized a forested area not far from a remote Wookiee village to which the Jedi Gungi had once belonged. At this time, Kashyyyk was occupied by the newly-formed Galactic Empire, aided by a cohort of Trandoshan mercenaries, who sought to claim the planet's resources and enslave the Wookiees.
In 18 BBY, Gungi, a survivor of Order 66 and the ensuing Great Jedi Purge, arrived on his native Kashyyyk with the assistance of Clone Force 99, a former clone commando squad which had deserted the Empire after the Order was issued. While en route to their destination, the clones unknowingly discovered the netcasters' nest, enshrouded in thick webbing. Wrecker, the most reckless of the team, produced a knife and began to slash at the websilk to clear their path. The disturbance aroused the swarm of netcasters, who quickly scuttled in their way and brandished their claws at the commandos. Although the Clone Force initially responded to the threat by raising their own weapons, the Wookiee intervened and relaxed the netcasters with a sign of peace. The group was then awarded passage through the arachnids' dominion.
Netcasters drag Trandoshan commander Babwa Venomor into their web.
Shortly after this encounter, the commando squad found only embers where Gungi's village had once stood, razed by the Imperial-Trandoshan occupiers. The discovery caused tensions to escalate dramatically, resulting in a firefight near the netcaster colony. The rogue clone commandos, joined by Gungi and several liberated Wookiees, clashed with a bask of Trandoshans led by commander Babwa Venomor. During the fight, the Wookiees summoned the local netcasters by pounding on the trees; this induced the creatures to appear and scatter the Trandoshans and clone stormtroopers. Gungi, meanwhile, fled deeper into the dark forest, luring the militant Trandoshan leader to follow. The reptilian alien gave chase, igniting a forest fire and unwittingly springing the Wookie's trap. Three of the creatures descended and swarmed Venomor, who retaliated unsuccessfully before he was encased in silk and hoisted into their nest.
Following the battle, Wrecker remarked that the trees—believed by Wookiees to be the true masters of the planet—had answered the Wookiees' petition to repel the invaders. The rogue clones then smothered the fire and departed the world.
Netcasters in an unfinished episode of Star Wars: The Clone Wars
Netcasters were originally set to appear in an episode of Star Wars: The Clone Wars, but the show was cancelled before the episode could be completed. A clip from the episode featuring the netcasters was shown at Celebration Anaheim in 2015 where eight of the creatures attacked several Wookiees and Clone Force 99 on Kashyyyk. The netcasters were shown to be aggressive and primitive, and were able to spit a spider-like web from a frontal appendix. The netcasters were not able to defeat the Wookiees and were all killed. The creature design was originally based on kinraths from the Star Wars: Knights of the Old Republic game.
Kinraths were brought into canon through a mention in the novel Join the Resistance: Escape from Vodran, but they were given no visual depiction. Elements of the cancelled Clone Wars story were later reworked into the sixth episode of the second season of Star Wars: The Bad Batch, entitled "Tribe." Early ideas for the episode featured the Wyyyschokk spider, which premiered in the then-recent canonical video game Star Wars Jedi: Fallen Order. Ultimately, the netcasters replaced the Wyyyschokk as a "slightly less fearsome" arachnid. The subtitles on Disney+ refer to the netcaster as a kinrath.