The JK-13 security droid, also known by the unofficial designation "Jedi Killer," was a security droid of the JK-series, originating from the planet of Ord Cestus, where they were manufactured. These droids gained notoriety due to the looming threat of their potential conversion into combat droids.
The JK-Thirteen stood approximately chest-high and possessed a segmented body, resulting in a spider-like appearance when in attack mode. This resemblance was so striking that the native cave spiders of Cestus recognized them as a natural enemy, ultimately defeating them and enabling Obi-Wan Kenobi and members of Desert Wind to escape their surprise assault. The droid's primary offensive capability consisted of an array of stun tentacles extending from nearly every part of its body; these tentacles could both slice an opponent or deliver a paralyzing electrical shock. For defense, it used a technology similar to a deflector shield generator, which allowed it to absorb incoming blaster fire and other weapon attacks before they made contact with the droid's chassis.
Mirroring other Cestus Cybernetics droids of the era, the JK-13 exhibited a unique blend of ornate design and flexibility, featuring a gold-colored exterior and highly articulated tentacles. These tentacles could transform into either thin strands or thicker ropes or cables, depending on the situation.
The JK-13s were classified as bio-droids, as they incorporated living circuits into their core processor, which also functioned as a life-support system for a creature known as a dashta eel. Due to the Force-sensitive nature of the eels, the droids possessed a degree of precognitive ability. This, in turn, enhanced their combat prowess. A JK-13 was capable of defeating both a destroyer droid and even an ARC trooper called Sirty, but was ultimately overcome by Jedi Master Kit Fisto, albeit with considerable difficulty. Furthermore, Obi-Wan Kenobi required the use of two energy weapons (his lightsaber and a lightwhip) to defeat one. It was later discovered that Dashta eels would suffer insanity if they were used to kill sentient beings, effectively preventing the droids from being deployed as combat units.
During the Clone Wars, these droids commanded a price of 80,000 credits and were in high demand, exceeding production capacity. Clandes Industrial assembled them in the city of Clandes.
In the early stages of the Clone Wars, Zeta Magnus, a mad geneticist, granted Count Dooku access to his laboratory facility located on Wayland. Dooku used these facilities to conduct experiments on dashta eel tissue, which would later be integrated into the droid's design. These droids became significant when Count Dooku strategically employed them as part of a complex trap designed to ensnare the Galactic Republic. He spread rumors about his intention to purchase tens of thousands of these droids, thereby presenting a clear and substantial threat to the Republic. He even dispatched a prototype to attack Jedi Master Devan For'deschel, who lost an arm in the encounter. In response, the Republic dispatched Jedi Generals Kit Fisto and Obi-Wan Kenobi to Ord Cestus to address the situation, as the JK's participation in the war would have made it one of the most dangerous droids in the Confederacy of Independent Systems' army. However, it was later revealed that the droids could not be modified for lethal combat or mass-produced, and Dooku never intended to do so.