Sibella is one of the students at Miss Grimwood's school in Scooby-Doo and the Ghoul School.
Sibella has lavender skin, long two-tone purple hair, red lips, aqua eyelids and green eyes. Her outfit consists of a dark purple dress with a knee-high slit, red flats, and a red belt. During exercises, she temporarily wears a red sweatband and pink leg warmers. She is tied with Phantasma as the second tallest girl in school, falling short of Elsa Frankenteen.
She can turn into a bat like all other vampires. Sibella's color scheme is incorporated into her bat form, as when she turns into a bat, she keeps her green eyes and aqua eyelids and has a lavender face, dark purple body, purple wings and red legs.
Sibella is very kind and polite. She seems to only dislike the Calloway cadets, Grim Creeper, and Revolta (and garlic, of course). She compliments other people often, showing her good people skills. She is also very helpful and generous, as she spent the last of her allowance on a pizza for Shaggy Rogers, Scooby-Doo and Scrappy-Doo. Another account of her being helpful is answering the door for Miss Grimwood while she was busy with Tanis. Sibella is not, however, above using her bat form to her advantage in sports such as volleyball and racing. She has a frequent habit of making vampire-related puns on words, such as "Fangtasic to meet you."
Powers and abilities
Unlike traditional vampires, Sibella is not adversely affected by sunlight. She has other vampire traits, such as the ability to transform into a bat.
She seems to be very creative with clothing, making a bat robe for her father and a fireproof robe for Matches. Revolta also called her strong, when she was trying to mind-control Sibella after the other girls had been taken, but Sibella fought and was the only one who lasted so long, so she may be the most powerful ghoul.
Sibella is presumably the daughter of Count Dracula's wife (although Dracula may have had multiple wives as per Bram Stoker's work), although due to different Hanna-Barbera writers, it's left ambiguous.