(Capcom's primary storyline)
- See also: Plant 42, Plant 43 (RE2 remake), and Ivy (RE2 remake)
Plant 43 (unofficially named as "Ivy") was an experimental bio-weapon series produced by Umbrella from data received at the end of the Mansion Incident.
The progenitor of the Plant 43 series was Plant 42, an irregular mutant that was created during the Mansion Incident in mid-1998. The bio-weapon series was quickly designed and improved upon the predecessor with the ability to walk. By September 1998 they were undergoing testing in both Raccoon City and at Sheena Island. During the Raccoon City Destruction Incident, a number of Plant 43s escaped containment, eventually leaving the Raccoon City Underground Laboratory and into the Raccoon Police Station. Despite the flaws in its design, enough research was continued to spawn the Ivy +YX variant by 2002, with the originals surviving long enough to be disposed of at the Caucasus Laboratory in 2003.