Dhuryam
this was the name of an immature World Brain, specially-bred by the Yuuzhan Vong to control the ecosystem of a planet. Grown from genetic material taken from the original World Brain of Yuuzhan'tar, dhuryams were related in many respects to the yammosks. However, the dhuryam was capable of widescale telepathic manipulation of its environment, where the yammosk used gravitic signatures to direct the actions of starships. Dhuryams were capable of coordinating the operation of huge numbers of Yuuzhan Vong bio-organic machines which were required to Vongform a world. A group of dhuryams were often grown together, and placed into direct competition with each other. As they developed the skills necessary to sustain an incredibly diverse ecosystem, the dhuryams matured. When they were ready, a ceremony known as the tizo'pil Yun'tchilat took place, in which only the strongest and most capable dhuryam survived. This one individual was then installed as the World Brain of a new planet. As the time of the tizo'pil Yun'tchilat approached, Yuuzhan Vong warriors were ordered to monitor their activities, for the increasingly intelligent dhuryams often used slaves to kill their rival dhuryams. This would unfairly taint the tizo'pil Yun'tchilat, resulting in a poor choice of World Brain.