The Goa'uld modified humans to create the Jaffa to serve as soldiers and as incubators for their young via an abdominal pouch. The story of the Jaffa is primarily told through the main character Teal'c. The Jaffa's look in the series was copied from the Egyptian look of Ra from the film. The Jaffa rely on the symbiotes for their immune system or will die a slow and painful death that can only be avoided by either acquiring a new symbiote or by lifelong regular injections of a replacement drug called Tretonin. Jaffa bear a symbol of their Goa'uld master's insignia on their foreheads, and the highest-ranking Jaffa in the service of a Goa'uld is known as the First Prime. SG-1 encounters three notable Jaffa factions: the all-female Hak'tyl ("liberation") lead by Ishta in season 7's "Birthright", the Ancient-worshipping Sodan in season 9's "Babylon", and the Ori-worshipping Illac Renin (meaning "Kingdom of the Path") in season 10's "Talion".