The strong but primitive Unas were the first hosts of the Goa'uld, and evolved on the same homeworld. Many still serve Goa'uld to this day as hosts and slaves, most notably in the service of Sokar -- who, before his destruction, used Unas as his envoys, threatening the people of his domain. Sokar is even said to have used an Unas as his own host body.
Those Unas who are free from Goa'uld oppression thrive on their homeworld of P3X-888, where they primarily dwell in caves and feed on the larval form of the Goa'uld symbiotes. Unas, though primitive, have a high potential of intelligence. After thousands of years they have developed means to avoid implantation by the symbiotes, including a necklace that protects the areas through which a symbiote may attempt to implant itself.
Unas have a fairly simple language of more than fifty different words, many of which Dr. Daniel Jackson has cataloged and learned to speak himself. The hierarchy of Unas is run by an Alpha-male leadership. It is unclear whether or not the species believes in a higher power, but they do have a religious system of sorts, incorporating chants into their daily lifestyle. Their creative areas are not lacking, as the Unas create primitive art within their cave dwellings.
Recently the aborigine Unas have come under threat by a clan of humans seeking to take the creatures and use them as slave labor. However, with help from SG-1, a group of formerly enslaved Unas (led by young Chaka, recently abducted from his home on P3X-888) have struck back at these humans.
Thor's Hammer - SG-1 learns of the Unas when Teal'c and O'Neill are trapped in an Asgard labyrinth with one.
Demons - The team faces a Goa'uld-ed Unas in the service of Sokar, who is oppressing a human colony and using them as hosts.
The First Ones - The S.G.C. finds the Goa'uld and Unas' original homeworld, where Jackson is captured by a young warrior named Chaka -- whom he manages to befriend.
Beast of Burden - Chaka is captured and taken to another planet by Unas traders, who use them as slave labor and beasts of burden.
Enemy Mine - SG-1 and a survey team are attacked by Unas on P3X-403, where they are planning to mine naquadah on the Unas' sacred ground. Chaka is brought in to negotiate a peace.