An orbalisk was a type of parasitic organism that existed in groups and was native to Dxun. These creatures remained dormant inside caves or other shadowy locations until they located a suitable host. They would then latch onto the host's skin to extract nourishment. Once attached, orbalisks rapidly reproduced and expanded, ultimately enveloping and suffocating their victim. However, the knowledge to create armor that prevented the orbalisks from covering the host's face, hands, and feet was contained within the holocron of Freedon Nadd, allowing them to keep this armor concealed.
Orbalisks possessed the capacity to feed on the Force-sensitivity of darksiders, possibly due to their inherent nature or their existence on Dxun, which was a significant source of dark side energy. The orbalisk armor was rumored to be so resilient that lightsabers struggled to penetrate it, essentially rendering the wearer invulnerable to lightsaber strikes. The armor's only vulnerability was the exposed joints at the neck and wrists, but these openings were so small that a lightsaber could barely cut through them. Nevertheless, orbalisk armor was unable to shield the wearer from electricity, as Darth Bane discovered when he was ambushed by Umbaran Shadow Assassins wielding Force pikes. Despite this, the Orbalisks provided some degree of protection against electrical attacks; the force pikes, although intended to be lethal, did not deliver a sufficient charge to incapacitate Bane. Orbalisks caused the wearer to experience pain, which amplified the wearer's dark side power, and when removed or killed, they released a highly toxic substance into the host's system.
The term "Orbalisk" originated from the Nikto language, suggesting that these creatures may have originated on Kintan. Orbalisks were toxic to ordinary beings and inflicted intense physical suffering on their hosts. However, Darth Bane managed to survive by allowing the orbalisks to consume the dark side energy within his body. In return, the orbalisks continuously released massive amounts of adrenaline and other enzymes into his bloodstream, augmenting his already considerable physical strength and enabling him to tap into even greater dark side power. However, this cycle could induce fits of uncontrollable rage in Bane if he failed to manage his anger. The orbalisks also secreted chemicals that allowed Bane to rapidly heal from almost any injury, even those caused by a lightsaber. Due to the benefits they provided to their host, the relationship between orbalisks and Bane was more symbiotic than parasitic.
Electricity, particularly at high voltages, was the only known threat to both the orbalisk and its host, although orbalisks attached to Darth Bane could safely absorb over a million volts. Upon death, orbalisks released toxins into the host's body, leading to death within days or hours, depending on the individual's resilience.
Removing orbalisks from a host was a difficult and potentially lethal process. The host needed to be in excellent health for the procedure to even be attempted. The initial critical step in removing a living orbalisk involved delivering an electrical shock—strong enough to stun the orbalisk but not harm the host—to its underside. This caused the orbalisk to weaken its adhesive grip on the host. Once removed, the orbalisks could be eliminated through electrocution. Bane wore orbalisks as living armor for a decade. In 990 BBY, Caleb removed many of the orbalisks covering Bane's body using this method after many of the parasites were killed by the Sith Lord's own Force lightning during a duel against five Jedi. Nearly a millennium later, when the New Republic was established, the Coruscant Livestock Exchange and Exhibition showcased these creatures, along with energy spiders and drochs, in its arthropod exhibit.
Orbalisks were first introduced in Kevin J. Anderson's 2001 short story, Bane of the Sith. This story was later incorporated into Drew Karpyshyn's novel, Darth Bane: Rule of Two. The Orbalisks play a significant role in the novel's narrative and its sequel, Darth Bane: Dynasty of Evil. They also appear in Legacy (2006) 5, where Darth Krayt consults the holocrons of Darth Andeddu, Darth Nihilus and Darth Bane, and the gatekeeper of Bane's holocron is depicted wearing orbalisk armor.