Resident Evil Wiki
Resident Evil Wiki
Prime universe
(Capcom's primary storyline)
Resident Evil 1 HD Tyrant

The development of "ε" was intimately related to the Tyrant Project.

"ε" (Epsilon) is a strain of the t-Virus developed by the research staff at the Arklay Laboratory.


The "ε" strain was developed over several years as a solution to the Tyrant Project's inability to create a supersoldier with the existing Beta II strain. The goal of this virus was to increase the likelihood of a human mutating into a powerful mutant while limiting brain damage. The first confirmed ε mutant was the Tyrant (T-002 Model).[1] In May 1998, during a surgical procedure, an airborne form of the virus was accidentally released from the Tyrant's body due to an incident caused in part by the Queen Leech. The virus spread across much of the facility, infecting a number of staff who mutated into Zombies and went on to infect more. Unlike earlier t-Virus strains, Zombies infected with "ε" will suffer another set of mutations in response to serious injury and become "Crimson Heads." These Crimson Heads were encountered during the Mansion Incident. A mutant strain of "ε" was later engineered, which instead mutated Zombies into "Lickers."

Further notes[]

  • "ε" and its modified variants are the most commonly occurring t-Viruses in the series. Most Zombies in Resident Evil; Resident Evil 2; Resident Evil 3: Nemesis; Resident Evil Outbreak, and Resident Evil Survivor are infected with it, though not necessarily all.