Kull warriors are genetically-engineered humanoid hosts implanted with a Goa'uld symbiote and given a full-body suit of energy-dissipating black armor. This armor makes the warrior virtually impervious to both energy and projectile weapons. It also allows the warrior to pass through force fields without resistance. Mounted on each wrist is a Plasma repeater, an energy weapon similar in principle to a Ma'Tok staff but with less power and a much higher rate of fire.
The humanoid host is artificially grown, then granted life through use of the Ancient healing device, the technology upon which the Sarcophagus is based. The host has vaguely human features but possesses a more skull-shaped face, white, translucent skin, and white eyes, along with their teeth showing. The hosts were grown to be the perfect soldier. To this end, the host has physical capabilities well beyond those of a normal human. They have great physical strength, endurance, and stamina, as well as a high degree of resistance to toxins and sedatives, even compared to that of Jaffa. They can also survive without oxygen for nearly ten minutes, because of a Breathing filtration system and their own natural lung capacity.
The many benefits the host has come at the cost of longevity. In making the host so physically powerful, it results in major organ failure within a short period of time. Selmak described it as the muscles being so strong that the heart was strained to keep up with supplying enough blood and oxygen to the body, resulting in cardiac arrest after a short lifespan.
The Goa'uld symbiote is implanted to prolong the life of the host, but even the symbiote's healing powers cannot fully compensate for the deficiencies in the host's body. While normal symbiotes possess genetic memory that would make them unreliable as footsoldiers, the Queen that spawned the symbiotes used did so without imparting her genetic knowledge, granting the Kull warriors all the benefits of a symbiote, while leaving the warrior a "blank slate" to be programmed to Anubis' liking.
Kull warriors were single-minded and persistent, completing their tasks with lethal efficiency. They would defend themselves if attacked during the execution of their mission, but only until there was no longer any threat being presented. They lacked initiative, and ignored anything that was not a clear threat or was not part of their mission parameters. Furthermore, the removal of any personality meant that the warriors do not fear anyone and were relentless in their goals. If it fell towards an attack that did not kill it in the process, it would simply rise up and continue on its assigned goal.
Due to their armor and impressive physical abilities, the Kull were almost unstoppable in battle. The Tau'ri and Tok'ra developed the Kull disruptor to negate the energy used by the Ancient healing device, thereby killing the drone within the armor without actually defeating the armor itself. Aside from that, only a tremendous amount of kinetic energy, such as a bomb, would have any hope of penetrating the armor. (SG1: "Evolution, Part 1", "Evolution, Part 2", "Death Knell")
- "I... serve.. Anubis."
- ―Kull Warrior[src]
- "Hail Anubis! Hail Anubis!"
- ―A group of Kull Warriors pledging their loyalty to Anubis.[src]
Using the knowledge he had gained along with information he had retrieved from Jonas Quinn's mind, Anubis began the process of creating a new type of foot soldier that would serve him as the Jaffa Rebellion had shown that these former servants that Anubis and other Goa'uld had depended on had grown increasingly unreliable.
Anubis would make use of both the Goa'uld Thoth and the base on Tartarus to serve as the primary breeding facility for these warriors. Once completed, the soldiers were sent through the Stargate into the territory of minor Goa'uld, where they would rampage through the Jaffa ranks to kill their Goa'uld Lord. Once the Lord was slain, his armies would be incorporated into Anubis's ranks which greatly increased his power.
SG-1 would eventually discover one of these warriors on its assigned task and learn of its creation. They would successfully capture one, after much effort, and discover where the creatures were being bred. A mission was sent out on Earth to find the Ancient healing device uncovered by the Goa'uld Telchak, in order to create an effective countermeasure. Anubis would learn of this and sent an attack fleet along with Kull Warriors to assault the Alpha Site, in order to prevent the development of the weapon but this ultimately failed although it resulted in the Ta'uri-Tok'ra and Jaffa alliance being dissolved due to all three races suspecting that the other was guilty. (SG1: "Evolution, Part 1", "Evolution, Part 2", "Death Knell")
After the Battle of Antarctica, the Kull were taken over by Ba'al, who used them in his own mission of conquest, killing several major System Lords, but Anubis' return effectively brought them back under his control. Most were wiped out during the Replicators invasion of the Milky Way galaxy. After Anubis and Oma Desala engaged each other in eternal struggle, the Free Jaffa were able to wipe out all of the remaining Kull warriors in the galaxy. (SG1: "Lost City, Part 1", "Lost City, Part 2", "New Order, Part 1", "Avatar", "It's Good to Be King", "Reckoning, Part 2", "Threads")
Major Leonard of the Atlantis expedition, who had previously faced Kull warriors in battle, experienced hallucinations of them when affected by a Wraith mind manipulator on M1B-129. These eventually became so intense that Leonard mistook his own team members for enemy soldiers, hunting down and killing them all. Continuing to see himself surrounded by super-soldiers, he chose to commit suicide by holding one of his fragmentation grenades to his chest and detonating. (SGA: "Phantoms")