. "The Tok'ra are a fictional alien race on the science fiction television series Stargate SG-1. They first appear in the season 2 episode \"In the Line of Duty\". In the show, the Tok'ra are biologically the same species as the Goa'uld who inhabit human hosts in a symbiotic relationship, and are opposed to the evil System Lords. They are one of the major offworld allies of Stargate Command."@en .