- For the character from The New Scooby-Doo Mysteries episode, Mission: Un-Doo-Able, see Mastermind (Mission: Un-Doo-Able).
The Mastermind was the disguise of Holly Graham.
Physical appearance[]
The Mastermind appeared as a tall and very slender male, with black hair and a pale gray complexion. He wore a three-button gray suit with yellow buttons, white gloves, black shoes, dark gray pants, and a dark gray cape that had a dark crimson lining.
Personality[]
The Mastermind was a cunning foe as seen by the traps he set up for the gang. The Mastermind purposely surrounded himself in mystery, presenting himself as a mystery that nobody would ever solve. He was highly egotistical, viewing himself as a mastermind criminal, and was unable to comprehend somebody outsmarting and defeating him. The Mastermind had a flair for the dramatic and loved clever wordplay, often making puns. He seemed to have a deep hatred of Mystery Inc. for unknown reasons, however, he appeared to have an encyclopedic knowledge of their cases and was seemingly able to bring back many of their old foes.
Powers and abilities[]
The Mastermind occasionally appeared as a hologram, and utilised holograms in creating facsimiles of Mystery Inc.'s previous foes, which gave him the ability to appear to have the following powers:
- Flight
- Teleportation
- Summoning ghosts and monsters
History[]
Scooby-Doo! Night of 100 Frights[]

Prof. Graham set-up in the Mastermind costume.

Holly Graham is the real Mastermind.
When Scooby-Doo enters the area of the roof where Velma is captured, the Mastermind suddenly appears behind Scooby. The Mastermind then introduces himself and confesses to being the one who brought back his old foes, the reason why Scooby is here, and he's the one who made Professor Graham disappear and claims Scooby will never figure out why he's doing this. The Mastermind then reveals he's captured most of Mystery Inc. including Velma. The Mastermind then asks if Scooby asks if he remembers the Black Knight, before summoning him onto the balcony, and disappearing in a puff of smoke.
Later, the Mastermind for unknown reasons is found carrying and running off with a tied up Daphne in the graveyard. Scooby spots this and rolls into the Mastermind, rescuing Daphne. The Mastermind gets upset and summons the Green Ghost in a puff of smoke before laughing and disappearing in his own puff of smoke.
After Scooby frees Fred the Mastermind sneaks behind Fred and slowly and humorously puts a barrel over him. Wanting to put an end to Scooby Doo once and for all, the Mastermind summons the Ghost of Redbeard. The Mastermind then flies away disappearing in a puff of smoke.
After the Gang makes a plan to finally capture the Mastermind, Scooby enters the Mastermind's lair, where he's on his control board currently getting excited about how "it will all be [his]" and how his "brilliant" plan is going perfectly. When he notices Scooby he is shocked to see that he entered his lair and is now determined to finally end Scooby Doo’s life. After Scooby Doo pushes two holographic projectors toward the Mastermind, Fred is able to project ghostly holograms of the gang which scares the Mastermind and causes him to fall down. Scooby pushes the Mastermind into an electric barrier causing him to fall to the ground.
The Mastermind slams his fist onto the ground as the Dressed For Supper Suck You Upper arrives to suck him up. The gang then unmasks the professor in the Mastermind costume, but Velma quickly figures out that Holly is the real Mastermind. She, Fred, and Professor Graham explain her plan, which was to use the Mastermind and holograms of their old foes to frame her uncle, who was stuffed into the tubes of the device off screen in a Mastermind costume as part of the plan to frame him, and while he was in jail she would steal her uncle's hologram machine and sell it in her own name.