The Jostrans are a species of sapients indigenous to the planet Munlali Mafir. There are arthropoidic in nature and could grow up to the length of a Human arm, essentially resembling slow-moving centipedes. Their civilization was wiped out when the living planet Zonama Sekot passed through their star system, causing prolonged periods of seismic and volcanic activity that was nearly responsible for their extinction; however a small population of Jostrans somehow survived the upheavals and eventually adapted to the new environment. They became symbiotic with the native Krizlaws, and would crawl into the mouths of their hosts before burrowing into their abdominal cavity. Once in this location they will wrap themselves around the spine and use their legs and fine hairs to infiltrate the neural tissue, thereby taking control of the body.
Because of this unusual configuration, the resultant species had two minds, a controlling and intelligent "rider" and a primitive animal mind. When the Jedi Order came through, following the trail of Zonama Sekot's retreat into the Unknown Regions soon learned how hard it was to influence the minds of these creatures because of how different both minds were, combined with the natural adaptive habit of the Krizlaws to form hunting packs of eleven hive-linked minds.