Yorik-Kul, alternatively known as surge-coral in the Galactic Basic Standard language, represented an organic technological creation employed by the Yuuzhan Vong. This surge-coral was inserted into slaves, thereby enabling them to receive telepathic instructions originating from a yammosk or a dhuryam. This process, however, had a significant drawback, as those who bore the implants would gradually forfeit their sentience, ultimately transforming into beings devoid of independent thought. These mind-altered slaves were then deployed as expendable units on the battlefield, serving to absorb incoming blaster fire. Furthermore, the presence of surge-coral induced a state of emaciation in its hosts and their eventual disappearance from the Force. In time, the Shapers refined the surge-coral, diminishing its adverse effects on the slaves, limiting the consequences to pain rather than complete mental subjugation.
Following his capture by the Yuuzhan Vong, Jacen Solo underwent implantation with surge-coral, which subsequently granted him the ability to sense the Yuuzhan Vong through the Force. A'Sharad Hett also experienced this procedure during his captivity under the Yuuzhan Vong. More than a century later, Hett, then known as Darth Krayt, suffered from the ongoing and lethal effects of the surge-coral. This motivated Krayt to seek out and utilize Cade Skywalker in an attempt to be cured of the implants.
Around 127 ABY, Sith Lady Darth Maladi and Zenoc Quah of the One Sith engineered a strain of Yorik-Kul. This variation, once implanted, would proliferate upon exposure to Force lightning, leading to intense suffering and, in some instances, death.