Plant 43

Plant 43 was a massive plant-based organism that appeared in the 2019 remake of Resident Evil 2. Following the Mansion Incident, the Umbrella Corporation continued to research the T-virus' effects on certain plants after learning about Plant 42, infecting a particular plant within their NEST facility beneath Raccoon City. The plant grew to an incredible size, sprouting countless vines that extended throughout the laboratory's greenhouse area. Plant 43 was carefully monitored and maintained, using herbicidal chemicals to limit its growth.

History
After the T-virus was unintentionally leaked inside NEST, Plant 43 continued growing unregulated as the facility went into lockdown. Many Umbrella researchers fell victim to the plant, becoming entangled in vines or being infected by its seedlings and transformed into Ivy Zombies.

During the Raccoon City Destruction Incident, NEST was visited by Leon Kennedy and Claire Redfield who managed to find a herbicidal agent and released it into the lab's greenhouse, killing Plant 43 and preventing it from spawning any more zombies. Any chance of it surviving and regenerating was voided when NEST's self-destruct sequence was activated, obliterating the entire complex.

Trivia

 * Plant 43 was originally an alternative name for the Ivy B.O.W.'s that appeared in the original version of Resident Evil 2.