What happens when you take one of the fiercest creatures of the sea, the great white shark, and inject it with the T-virus? You get Neptune, an overgrown, highly aggressive and very powerful mutation of the great white. Neptune is the result of the curiosity of Umbrella when they wondered if they could create sea monsters. Well, they succeeded.

Neptune was code number FI-03 in the Arklay labs. Three Neptune creatures were kept in a large tank underneath the guardhouse. Two of them were not fully matured. The father Neptune grew to enormous size and had the capability to destroy railings and reinforced glass windows. The STARS team came face to face with the Neptunes; some reports say that Richard Aiken was eaten alive by the large Neptune. The Neptunes were defeated when the water in the tank was drained by one of the STARS members. Due to their obvious limitation to the water the Neptune will never be used as a B.O.W.