Holly Graham (Grey DeLisle) is the hidden villainess of the 2002 Scooby Doo video game Scooby Doo! Night of 100 Frights. She was the niece of inventor Professor Alexander Graham and lived with him in his mansion, Mystic Manor. She was also an old friend of Daphne Blake, a member of the Scooby Gang. When she learned that Alexander had invented a hologram creation device, the evil Holly plotted to have her uncle imprisoned so she would be free to pass his invention off as her own and claim all the money that would result from it.
Holly's plan began with her taking Alexander hostage and stashing him out of sight. She then called Daphne and asked her and her friends (Fred, Velma, Shaggy, and Scooby Doo) to come investigate his "mysterious disappearance", while also claiming Mystic Manor to be haunted. Using her knowledge of the gang's past cases given to her by Daphne, the villainous Holly began terrorizing the gang with hologram recreations of their former foes, including an original monster dubbed "The Mastermind", kidnapping the members of the Scooby Gang and holding them in various parts of the manor. She also used her uncle's invention to create a hologram of herself to avoid suspicions.
Toward the end of the game, Holly used another of Alexander's creations to dress him as The Mastermind and kept him stuffed in a chute to deposit the dazed man before the Scooby Gang to frame him. But Velma, having found various clues hinting at Holly's scheme, used her glasses to make the hologram wall hiding the villainess' hidden laboratory disappear, exposing Holly as the true culprit. Holly revealed her motivation when confronted by Velma, revealing her inner greed. Holly was shown looking defeated as the gang shared a final laugh at one of Shaggy's antics, but it was never revealed if Holly faced prison or some other form of punishment for her actions.
- Ironically, Grey DeLisle was also the voice of heroine Daphne Blake. Grey voiced three villainesses on What's New, Scooby Doo?, portraying the evil Mademoiselle Chantal in Season Two, and villainesses Verona Dempsey and Galina Korzhakov in Season Three. She also appeared in 2014's Scooby-Doo! Frankencreepy as the voice of the evil Mama Mione.
- Grey also voiced eight villainesses on Be Cool, Scooby Doo!: Carli, Nate's villainous mother, Mrs. Clune, Lori Logan, Bubby, Lori Walsh, Ms. Anja, Mrs. Baker, Karen, and Rose.
- Grey DeLisle also lent her voice to Mitzy, a villainess from Johnny Bravo, and villainous dominatrix Tammy Jane from Brickleberry. She is arguably most well known for voicing Azula from the anime series Avatar: The Last Airbender.