Eveline is the main antagonist of Resident Evil 7: Biohazard. Initially presented to the player as the catatonic elder of the Baker family, Eveline is later revealed to be a genetically enhanced human, an "E-Class" bio organic weapon (B.O.W.) codenamed "E-001" and the first successful E-Class prototype. She infects her victims using mold and fungus, allowing her to create a legion of people that she perceives as her "family", and thereby command and convert them into the "Molded".
Eveline was created by a criminal organization called "The Connections" with the help from H.C.F, one of the late Albert Wesker’s companies, as part of their NEXBAS (Next-generation experimental battlefield superiority) initiative: creating a B.O.W. capable of blending in with the population, to indirectly neutralize combatants while converting enemies into allies. The Connections sought out Mother Miranda by offering to their assistance in her agenda to revive her long deceased daughter Eva, Miranda providing them a sample of Progenitor-enhanced fungus called Mutamycete that is infused in an embryo cloned from Eva's DNA. The project ultimately folded due to reservations regarding methodology and the difficulty of controlling the resultant product B.O.W., particularly in comparison to other projects. Due to the E-class bioweapon's destructive abilities and mind control capabilities, its project materials were sought after by rival companies. This state of affairs resulted in Mia Winters and Alan Droney, members of The Connections, traveling with Eveline upon a cargo ship alongside Miranda bound for a facility in Central America. When a hurricane hit the ship, Eveline became unstable, infecting Alan and turning the crew into the Molded. Mia has no choice but to track Eveline and fend off her Molded minions. Mia was helpless as Eveline killed Alan and subsequently infected her. Mia attempted to send Ethan Winters a second video message prior to the ship's destruction, wish him a happy life and urging him not to search for her.
Eveline and Mia were both later recovered and taken in by the Baker family, who happened upon the ship wreckage in the Louisiana bayou. Eveline infected the Bakers within the month and placed them under her control. Two years after, Eveline's mind and body were deteriorating rapidly due to lack of her medication and the degenerative effects of her condition, prompting her to demand the Bakers to add more people to her family by kidnapping or killing them. Zoe was the only one not affected by Eveline's mind control while her brother Lucas was subsequently cured on the initiative of the Connections' leadership and pretended to work with his family, cognizant that Eveline was a threat.
Once Ethan arrives at the Baker estate, he is assisted by Zoe. When he finally learns of Eveline's origins, he used the equipment in the lab deep in the nearby Salt Mines to develop a necrotoxin using Eveline's DNA to kill her. He succeeds in injecting Eveline with the necrotoxin, disrupting the hallucination concealing the aged woman she became before mutating into a giant grotesque form as her powers spiral out of control. With the help from Chris Redfield and Blue Umbrella, Ethan kills Eveline with the B.S.A.A. quarantining Dulvey to purge the remaining traces of the mutamycete.
A ghostly apparition of Eveline appears before Ethan during the events of Resident Evil Village after Miranda ripped his heart, tormenting Ethan by revealing that he was killed by Jack Baker and only survived because he was infected with her mold.