Gutretee were a crystalline sentient species indigenous to Isis. The Gutretee were immune to blaster fire.
Gutretee were an honorable, single-gender race living in primitive nomadic tribes, gaining nourishment from the mineral deposits growing on the surface, and from eating crystalline animals. They were very aggressive in nature; most of their rituals and passage rites involved fighting. Newcomers were often challenged to duels. While these duels were often misconstrued as death matches, they were instead a means of sharing cultural history. The victor earned the right to hear the tribal history of the loser.
Some tribes were allied with the Rebel Alliance and worked in the mines helping to provide construction materials, while other tribes hated the Alliance, considering themselves at war with the off-worlders. Decades after Bail Organa arranged for the colonization of Isis, a majority of the Gutretee learned to speak Basic with thick, halting accents.