The Ithullans originated from the planet named Ithull, and they were a humanoid species. Being indigenous to the Stenness Node, they belonged to the group of 25 species that were known together as the "Nessies".
The Mandalorians engaged in warfare with the Ithullans two centuries before the Galactic Empire rose to power, almost causing their complete extinction. By the time the Battle of Yavin occurred, the Ithullan population was drastically reduced, with only a small number of Ithullans remaining; some could be spotted in Mos Eisley on Tatooine. It is known that Gorm and Dyyz Nataz, who were both bounty hunters, wore armor that was of Ithullan make.