Carol (Vanessa Marano) is the hidden main villainess from the 2018 straight-to-DVD film, Daphne & Velma. She introduced herself to new student Daphne Blake as a senior student advisor to Ridge Valley High.
In actuality, not only was Carol not a student at Ridge Valley High, she wasn't a teenager. Carol was actually a 26-year-old working at Bloom Innovative, and she was the original inventor of the new Azalea 9 phone. However, as time went by, Carol became pressured to think up new ideas, and that along with her desire to stay on top and run Bloom Innovative led to a villainous plot that involved stealing ideas and taking them as her own. She built a Brainwaver machine and first used it on Daphne's mother, Elizabeth, leading to the creation of Match Mouth.
Additionally, the evil Carol hacked the Azalea 9 phones and turned them into hypnotic devices before giving them to the students. The villainess activated the phones and lured her victims to the hallways behind the lockers, where they would be subjected to the Brainwaver; after which Carol would use their ideas to create her inventions. As part of the ruse, Carol used a hologram of Tobias Bloom to mask her role as the mastermind, while also acting sweet natured to Daphne and Velma Dinkley to cover for her ruthless and ambitious personality.
Daphne and Velma believed that Tobias was the culprit, and it appeared to be confirmed when they faced off against him in his office at Bloom Innovative. However, when Velma tossed one of the robotic spiders at Bloom, she and Daphne realized that he was a hologram, as the object went through him. Daphne also recognized "Tobias Bloom" as a male model from her time in Japan, and the duo investigated further to find out who was operating him. They spotted Carol in a pod operating, though she portrayed herself as a kidnap victim of Tobias. When Daphne stated that Carol couldn't have been abducted due to Tobias being a hologram and Carol not being drone-like like the other victims, Carol quickly dropped the facade and revealed her true villainous demeanor.
Carol's scheme was uncovered by Velma, while Daphne realized that Carol couldn't be a teenager due to everything she had been doing lasting for many years. The scheming villainess revealed that she's 26, and as for a motive, she callously stated that she did it for money and power. After failing to coerce Daphne and Velma to let her go, Carol was arrested (off-screen) for her criminal actions.