Spinerays were creatures used by the Yuuzhan Vong.
Serpentine in appearance, the spinerays were naturally predatory, but they also served shapers as tools for their ability to monitor neural pathways. Spinerays were kept in their unshaped forms as well, as they were useful in rooting out undesirables from a location. They were also used to torture victims during interrogations. There were at least two types of altered spinerays.
The provoker spineray was useful in reshaping or brainwashing prisoners. Provoker spinerays could target selective neural pathways corresponding to memory, and would cause pain if one tried to access the forbidden memories.
The tracer spineray was used to stimulate pain receptors as well, but on a less severe scale. They stimulated pain receptors at joined flesh after a Yuuzhan Vong underwent an escalation, to see if the nerves of the new limb were connecting to the Yuuzhan Vong's body.
The interrogation spineray links to the victim's neural system and activates the pain reception. If the spineray senses that the victim is trying to lie or resist it will make the victim feels like his whole body, all his nervous terminations and internal organs are catching fire. Successive attempts to resist may lead to the victim's death.
A provoker spineray on Tahiri Veila
An interrogation spineray was used on Dibrook's Shaper research facility on the captured Jedi Yuledan during an interrogation attempt by commander Tsalok.
A provoker spineray was used on Yavin 4 by Master Shaper Mezhan Kwaad and her adept Nen Yim on the captured Jedi Tahiri Veila. Using the organic creature, the Shapers attempted to map her neural system in order to Shape her into a Yuuzhan Vong thus creating another personality called Riina Kwaad.
After Warmaster Tsavong Lah's implantation of a Radank claw, a tracer spineray was used to check his pain receptors in order to determine if the implant was rejected or not.
By the time of the Jeedai heresy on Yuuzhan'tar, High Priest Jakan believed that the only way to remove the heresy was the destruction of the heretics that resided underground on the world shaped Coruscant. To that end, he petitioned Supreme Overlord Shimrra Jamaane that wild spinerays were to be introduced underground where they would kill the heretical Shamed Ones. However, the problem with the plan was that it would be difficult to kill the wild spinerays and the plan was rejected.