The Jaffa (Second Human Empire: Hamo Yuik'nin Oiu'uiki, Borg Designation: Species 7724) are an offshoot of humanity, genetically engineered by the Goa'uld. They have an abdominal pouch which serves to incubate larval Goa'uld. The infant Goa'uld provides strength, longevity, and good health, at the cost of supplanting the Jaffa's natural immune system, making them dependant on the Goa'uld for more symbiotes. The Jaffa have a warrior culture and form the armies of the Goa'uld. Most Jaffans joined the Alliance of Nations, while some of them joined to the Axis of Empires.
The Jaffa were created from the human slaves taken from Earth by the Goa'uld. They were genetically altered to function as incubators for Goa'uld young. The process ensures compatibility and the success of implantation once the Goa'uld matures and takes a host. Jaffa children are implanted with a larval Goa'uld when they reach the age of implantation, approximately ten-years old. Honored Jaffa are granted a ceremony of Prim'ta during which the implantation is performed. If the implantation is not completed before the Age of Prata (puberty), the Jaffa child will die as a result of a failing immune system. During the implantation process, an "X" shaped mark is cut on the abdomen to create a pouch for the larva. This pouch never completely closes meaning the larval Goa'uld inside can be physically inserted or removed at any time. The symbiote replaces the immune system completely and without one a Jaffa will die a painful death in only a few hours.