Jaffa

The Jaffa are a subspecies of Humans who were genetically engineered by the Goa'uld in Earth's antiquity, in order to serve as both their enslaver's soldiers and incubators for their young.

Biology
While the Jaffa are nearly identical to their human "cousins", there are some differences. The most obvious of these is an abdominal pouch, accessible to the outside world by an X-shaped slit. This pouch serves as the incubation chamber for larval Goa'uld, known as the Prim'ta, as incubating them thusly will improve their ability to successfully take a host once mature from the natural 50% to nearly 100%. While this pouch is not in truth natural to the Jaffa, the Goa'uld have a device capable of quickly transforming any Human subspecies into Jaffa by installing a pouch in them; however, this destroys their immune system immediately in order to make the Jaffa dependent on the Goa'uld growing inside of them.

The incubation process is a mutual symbiosis, and having a prim'tah inside of them grants each Jaffa enhanced strength, health, healing, and longevity (increasing their lifespan to an excess of 150 years). Unfortunately, it also has its major downsides: The symbiote in their abdomens effectively replaces the Jaffa's immune system in its entirety, and if (and, for that matter, when) the symbiote is removed, the Jaffa host will die a long and painful death. It is during the Jaffa equivalent of puberty - the Age of Prata - that a prim'ta must be implanted within them. The Age of Prata comes about around the age of 13.

Another noticeable difference between the Jaffa and Humans is that the Jaffa do not require sleep, but instead must engage in a form of meditation called kelnormin in order to synchronize with their symbiote. During dangerously deep states of kelno'reem, the host gains the possibility to communicate with their prim'ta.

Culture and society
Because they have always been the slaves of the Goa'uld until quite recently, they don't yet seem to have many cultural traits worth mention. Of those that are worthy, however, included their great sense of honor and nobility. While only men would serve the masters as warriors, their entire culture was built around the warrior, and concerned every Jaffa. Through this, they became a strong, courageous, and proud warrior people, with an incredible strength of mind, as well. As their years wane on, each of their kind will gain not only experience, but also lucidity of mind and wisdom as well.

However, those in service to a Goa'uld must bear a black tattoo of their master's personal insignia on their foreheads. Jaffa who are the highest-ranking in service to any specific master become known as the First Prime, and have their regular black tattoo replaced with a raised gold insignia. This insignia is created by baring the bone with a special knife and filling the wound with molten gold. This process is described as very painful. It is of note that other high-ranking Jaffa may bear similar silver marks instead. This may indicate that the Jaffa only has a certain amount of time to become either a regular high-ranking servant or a First Prime, before the metal is poured into their head.

Elite guards of powerful Goa'uld sometimes wear armored and ceremonial helmets shaped like their master's symbolic animal, which are intended to intimidate the Goa'uld's enlsaved human populations. These helmet-masks are made from articulated metal plates that can fold in on themselves to reveal the face.

History
Requiring a rare substance known as Naquadah that powers all of their technology, the Goa'uld sought to populate the entire Milky Way and mine for the substance that they so desperately required. Through this means, they sent slaves to other worlds via a device they called the Chappa'ai; known to Earth as the Stargates. Unfortunately for them, this all seemed to come to an end around 3,000 BC, when a rebellion led to Ra's retreat to Abydos as well as the burial of Earth's Stargate.

However, the Goa'uld successfully brought some slaves with them during their retreat, and it was these whom became the first Jaffa when some of their numbers were implanted with infant Goa'ulds. As a reward for carrying the symbiote prim'ta, it would protect its host and grant them a longer lifespan, as well as heal any minor medical problems that they would come across during that extended period of time.

For thousands of years, the Jaffa then faithfully served the various Goa'uld masters as soldiers for their armies and servants of all kinds, as they had come to see their masters as gods. Despite this, there was once a splinter group known as the Sodan warriors, who first understood that the Goa'ulds were not in fact gods. Likely due to their far-weaker strength of numbers in comparison to the Goa'uld Empire, they were forced to run and hide.

A millennium later, two renegade Jaffa known as Teal'c and Bratac made substantial efforts in order to create a new Jaffa Rebellion, and with the help of the Tauri and Tok'Ra the Goa'ulds were finally defeated, setting the Jaffa free.