|This needs a stretch. (Feel to remove when satisfied of completion.)|
* Physical appearance is incomplete.
* History is incomplete.
She has her hair in pigtails and wears very large square glasses.
She is proud of her high IQ of 195 and believes herself well-qualified to take over the town.
Skills and abilities
She is a persuasive leader of younger children. In prison she built up combat abilities, including taking up weight lifting, being able throw a barbell at Krampus before it abducts her, and the ability to kill with her braids.
Scooby-Doo! Mystery Incorporated
Mary Anne wanted to run Crystal Cove her way with no adults so she dressed up as Que Horrifico to scare the adults out of town. When she played the music, the children donned their monster disguises and scared away the parents.
When it came to the monsters cornering Mystery Incorporated, the television was turned on to a cartoon distracting the children. When Que Horrifico tried to run, it was caught by surprise by the police car carrying Sheriff Bronson Stone and Mayor Fred Jones, Sr. and fell into one of the nets. Mystery Incorporated unmasked Que Horrifico revealing Mary Anne who explained her plot to drive away the parents and take over Crystal Cove. One of the children stated that her plan wouldn't have worked anyway. Sheriff Stone then grabbed Mary Anne with handcuffs and took her away while ranting to her about costing the town a fortune with merchandise such as Que Horrifico t-shirts, Que Horrifico Pan Flutes, Que Horrifico Dance CDs, and Que Horrifico... when Mary Anne replied, "Ok ok! I see your point."
- She appears to have sinus problems, as she makes thick, phlegmy sounds when she speaks. In the second season, she's developed the habit of spitting.
- The end credits of The Song of Mystery, she's credited as Mary Anne Geerdon. In the end credits of Wrath of the Krampus spelled her name as Mary-Anne Gleardon, but on the letter to the parole board her name is spelled Mary Anne Gleardan.