B.E.V. (Built to Eradicate Viruses) is a character that once served as the main antagonist of Ralph Breaks the Internet. She is the head of Interneat, an antivirus software. Despite serving a noble facility, Bev is a cold-hearted figure with a fascist streak.
Early versions of Ralph Breaks the Internet included a villainous character for Ralph and Vanellope to overcome; not unlike King Candy in Wreck-It Ralph. Bev was the overlord of Interneat, a powerful organization built to eradicate all viruses in the Internet. The character was modeled after co-director Phil Johnston's mother, and went through a number of iterations over the course of development.
The most notable iteration of Bev was a manipulative villain that posed as a sweet, Midwestern lady. In another version, she was an antagonistic, yet well-meaning security official that sought to protect the Internet by any means necessary. In some versions even, Bev was a militaristic male character with a cold and formal demeanor. Eventually, the filmmaking team opted to cut Bev and the idea of a villain altogether in favor of a narrative in which Ralph's internal struggles served as the antagonist.
Development of Ralph Breaks the Internet coincided with development of a virtual reality experience based on the film. The team behind it, Void, needed a villain for the attraction. They approached Pamela Ribon and requested a villainous security system, to which Ribon responded by introducing them to Bev. Ribon passed over the news of Bev's involvement in the attraction to Phil Johnston and co-director Rich Moore, who were delighted to know the character had been resurrected.
Bev serves as the main antagonist of Ralph Breaks VR. In the attraction, Ralph and Vanellope sneak guests into the Internet to enjoy some online games. Unsurprisingly, Ralph's wrecking causes problems. Ralph and the guests are detected as viruses, prompting Bev to unleash her antivirus drones upon the heroes.