The t'salak was a Force-sensitive creature of unknown origin, although it was possibly Sithspawn. The t'salak resembled an oozing black blob. It had no sensory organs, but was was still cunning and would use its sticky tendrils to lash out with comparatively good accuracy and power. As it was filled with chaotic thoughts, it could induce blinding rage into sentient beings just by touching them. It could not be killed by solid objects, but was very susceptible to cold and vacuum. Its spawn appeared to be small pieces that had broken away from the main body and were weaker and more easy to destroy than the adult t'salak.
A specimen was first discovered in the jungles of Cularin and was subsequently imprisoned inside a Force-imbued urn. The urn was buried inside a cave and guarded by Tarasin villagers for generations, until it was stolen by the Dark Jedi, Raik Muun. With the help of scientists, she learned how to divide the t'salak into multiple independent entities of equal power. Muun used hers to try and disrupt a peace conference by inducing the Jedi mediators into blinding rage. Her plan failed, but Jedi Master Kirlocca was killed while defending himself against them. Muun also took some with her on a mission to the ruins of the Almas Academy.