The "Dragon" was birthed from Spike, a prison dog that was impregnated by a facehugger. The Runner violently emerged out of the dog, coincidentally during the funeral for Newt and Corporal Hicks, who were both killed when the escape pod crashed on Fiorina 161. The "Dragon" hid in the prison's air ducts while it matured. Thomas Murphy, who was cleaning the air ducts, died when he wandered near it. Murphy heard noises coming from a hole in the wall, and went to investigate, believing it to be his dog, Spike. He soon realizes it is not his pet, but the juvenile alien. Before he could withdraw his head, the alien spat acid into his face. He stumbled backwards into a ventilation fan, shredding him instantly.
After the "Dragon" had molted and reached its mature state, it began a killing spree, killing prisoners Boggs and Rains. Golic, who witnessed the "Dragon" killing the inmates, became obsessed with the creature and dubbed it "Dragon". The Lurker then went into the prison's infirmary and killed Clemens, a medical officer. It then confronted Ellen Ripley but spared her, as it sensed the Queen chestburster within her. It later caused further pandemonium by killing warden Andrews in front of everyone in the mess hall. Due to the absence of weapons in the prison, Ripley rallied the inmates and formulated a plan to pour highly flammable toxic waste into the ventilation system and ignite it. However, the "Dragon" intervened, causing a massive explosion and resulting in several deaths.
The remaining survivors later form a plan to lure it into the foundry's molding facility and drown it in molten lead. The bait-and-chase style plan resulted in the death of nearly all the remaining prisoners, leaving only Ripley, Dillon and Morse still alive. Dillon nobly faces the "Dragon", hoping to stall it long enough for Ripley and Morse to pour the lead. After killing Dillon, the "Dragon" was drowned in molten lead. The "Dragon", now covered in molten metal, leaped from the extremely hot lead and attempted to kill Ripley, but was killed when she turned on the fire sprinklers. The rapidly fluctuating temperature of its carapace caused it to shatter via thermal shock.