"Number Six... I remember this one. Mr. Weyland thinks there might be something special about it..."

Growth and experimentation

Specimen 6 was birthed in a controlled environment at the Weyland-Yutani research facility on BG-386 by Dr. Groves and his team. Having gestated inside a human host (a restrained technician), Specimen 6 was born directly into a containment tube, just like the other Chestbursters that had been collected at the facility. However, when scientists entered the room to retrieve the creatures, Six burrowed back inside its host's chest and emerged from the man's mouth to escape captivity. Dr. Groves promptly activated the emergency coolant systems in the room, killing the scientists and subduing Specimen 6, but the infant Xenomorph was spared at Karl Bishop Weyland's insistence, who was impressed with its intelligence.
Six was placed in a secure harness and branded with the number "6" on its forehead. Over time, Six developed to maturity and was subjected to numerous tests by Weyland-Yutani designed to explore its lethality, including being allowed to kill technicians and an armed security guard. During one such test, Six heard the call of the captured Matriarch and attempted to escape, but was gassed and recaptured by Groves.When Weyland finally opened the Yautja Pyramid located beneath the research facility, a powerful electro-magnetic pulse was unleashed, shutting down all power in the research complex and consequently allowing Specimen 6 to slip out of its restraints. Six immediately escaped into the facility's ventilation ducts and quickly freed more of its siblings from another nearby holding facility, before the Xenomorphs moved to the large lab where the Matriarch was being stored, seeking to free her. Six killed the guards and shut down the power to the Matriarch's restraints, before opening the main tramline doors, allowing it and the other Xenomorphs to escape into the jungle before Weyland-Yutani could respond. The Xenomorphs made their way to the nearby Freya's Prospect colony, where the Matriarch set up her Hive within the ore refinery. Six and the other Warriors moved into the colony itself to harvest the colonists and eliminate the security forces there. A force of Colonial Marines soon arrived on the planet to combat the rapidly spreading infestation, and Six encountered soldiers armed with M260B Flamethrowers in the sewers beneath the colony complex. With the colony's residents all used as hosts for more Xenomorphs, Six moved into the surrounding jungles, disabling the Marines' communications network and infiltrating a Marine outpost there to slaughter those inside. While a group of Marines managed to successfully trap Six inside one of the office units, Six smashed the lights in the room and hid in the shadows, escaping when the Marines moved in to investigate. Inside the outpost's command bunker, Six harvested more civilians and manipulated the controls to the rear gate to make its escape.