- "UL-119-2 remains our most physically dominant and remarkable specimen, surviving longer than any hybrid developed with embryonic stem cells. I remain baffled as to why this is so. The bond she seemed to have developed with EV-184-9 continues to intrigue me. All at once, this mighty, matriarchal beast can be calmed into quiescence by no more than a glance! Dr. Torres has developed a containment module for UL-119-2. He believes that by suspending her in cryptochromic fluid, the pyschomagnetic bond she and EV-194-9 appear to share could be amplified. I am skeptical but willing to entertain his flight of theoretical fancy."
- —Dr. Niles Samson on the Matriarch.
The Matriarch, or Subject UL-119-2, was the first Locust Drone created at Mount Kadar Laboratory, and was the original Berserker, the female species of the Locust Horde. It was created by Dr. Niles Samson and his team of scientists by combing the embryonic stem-cells of Myrrah, a human with a natural immunity to Imulsion, and Sire DNA in order to create a new race of human hybrids that would be immune to Imulsion and be used as a strong military force. The Matriarch was the "mother" of the Locust Horde and reproduced the first generation of Drones. The Matriarch had an innate ability to integrate her mind into the Hivemind and allowed Myrrah complete control over the Locust. She was what connected Myrrah's daughter, Reyna Diaz, and her granddaughter, Kait Diaz, to the Swarm. Only one has been known to exist.
As the scientists at Mount Kadar Laboratory continued to study the mutagenic effects of Imulsion on humans, seeking the means to create an evolutionary leap for humans under the direction of Dr. Niles Samson, they discovered that Myrrah, their most promising human subject, had a telepathic connection with the Locust. To nurture and enhance this ability, Samson had the Matriarch created using the DNA of Myrrah and a Sire. The Matriarch was permanently housed within a stasis tank and connected to a mind-machine interface, through which Myrrah was able to attune with the Matriarch and use it as focus, strengthening her connection to and control of the Locust for the sake of turning the Locusts into COGs's obedient powerful soldiers.
After Dr. Torres became disillusioned with the lab's work and fled, taking his and Myrrah's daughter, Reyna, with him, Samson lied and told Myrrah that Reyna had been killed. Instead of settling the matter, Myrrah was enraged and directed the Locust to rebel against the lab's staff and guards. Myrrah and the Locust broke free and traveled to Mount Kadar, where they eventually created the Locust Horde, while the remaining personnel variously succumbed to their wounds or were frozen solid by a cryogenic purge of the facility that Samson had initiated before he bled out. The Matriarch remained alive and preserved within its stasis tank, which was maintained by an AI construct of Samson's personality over the following decades.
In 42 A.E., Kait Diaz and Delmont Walker entered the lab in search of information about Kait's family and her connection to the Swarm. There, the Niles AI explained how the Locust were created, why Myrrah rebelled and hated humanity, and how Kait had developed the same telepathic ability as her grandmother. In order to sever that telepathic connection, Kait used the interface with the Matriarch, which was connected to the Swarm hivemind. Inside the Hivemind, Kait encountered the Matriarch who grabbed her and brought Kait to her mother. Kait inadvertently awakened her mother, now the Swarm Queen before Del severed the link. The Niles AI betrayed Kait and Del and turned the lab's defenses against them, and the Matriarch was freed in the process. Near the exit, the Matriarch burst into a frozen cavern and destroyed the AI. Kait and Del managed to kill it and escape the lab.
The Matriarch is a powerful, heavily armored enemies. Like Berserkers, she is blind and relies on her sense of smell and hearing to locate her prey, which she usually attempts to kill by bludgeoning with her fists. The Matriarch has other weapons at its disposal than its overwhelming brute strength, however. Its scream is loud enough that it can temporarily incapacitate anyone within its range, and it can attack at range by flinging the spikes on its back. These spikes are explosive, and if not removed quickly, will detonate and kill anyone that they impale.
The Matriarch's weakness is a large, glowing blister on its back. This can be difficult to shoot since the Matriarch will quickly turn its attention toward anyone who lands a hit. The best way to fight the Matriarch in-game is to shoot the ice out from under it and drop the creature into the freezing water. The Matriarch will freeze solid for a short period of time, giving the player the opportunity to shoot it in the back before it breaks free. Repeating this process several times will kill it.
- Gears 5 (First appearance)