Eliminators were primate-based B.O.W.. They were first featured as enemies in Resident Evil Zero and in Resident Evil: The Umbrella Chronicles.
The Eliminator was one of several early prototype weapons developed exclusively by James Marcus during the test phases of the t-virus capabilities as a weapon, but before the selection of a specific host for the strain. Developed alongside the Eliminator were the Lurker and Plague Crawlers, further displaying Marcus' fascination with the use of unlikely subjects as deadly weapons.
Although initially deemed a successful product, the Eliminator was found to have undergone significant decline in overall intelligence as a result of t-virus administration, which was supposed to be its greatest asset to Umbrella's B.O.W. program. Mass-production of the Eliminator was canceled and only a handful of specimens were preserved for further testing and general research. Marcus instead turned his attention to the potential that human subjects presented as virus hosts, later unwittingly providing Dr. William Birkin and S.T.A.R.S. Alpha team Captain Albert Wesker with the first scraps of information pertaining to the creation of the Tyrant-class B.O.W. The existing Eliminators were left to rot, although James Marcus released them on Rebecca Chambers and Billy Coen after they had infiltrated the Umbrella Research Center. Marcus noted that the remaining Eliminators had been exhausted by negligence and hunger, suggesting they had not been at full strength when encountered. Some of these B.O.W.s were mass-produced in the Russian Umbrella Facility and were released in 2003 by Sergei Vladimir during the outbreak in order to eliminate the anti-Umbrella forces led by Chris Redfield and Jill Valentine from proceeding any deeper into the facility.