- "Prometheus Fire. The divine gift to humanity. Z–01 contains the genome responsible for the Xeno's ability to accelerate and slow down its metabolism at will. Its symbiotic capableness easily rewrites the host's DNA through its blood. This is a much needed and well overdue upgrade for humanity. We simply cannot wait for evolution anymore."
- ―Rook (from Alien: Romulus)
A rat mutated by the Z–01 compound
Z–01 was a mutagenic compound extracted from a mysterious alien pathogen by a Weyland-Yutani Corporation science team aboard the space station Renaissance. Originally developed to augment the physiology of human colonists so as to allow workers to withstand adverse environmental conditions, the substance played a role during an incident in 2142.
Z–01 was capable of resurrecting and restoring a crushed rat, but also mutating it to the point of death. When the salvager Kay Harrison injected the compound into herself to heal injuries sustained during a Xenomorph outbreak on the Renaissance, it healed her wounds; however, it also mutated the unborn fetus inside her. After the resulting lifeform was born, Harrison produced a mixture of breast milk and the Z–01 compound on which the lifeform fed, killing her.