Sally McKnight

Sally McKnight, better known as Thorn, is the guitarist and lead singer of the goth band, the "Hex Girls". Her hometown is located in Oakhaven, Massachusetts.

She is 1/16th Wiccan on her mother's side, although this would be impossible as Wicca is a 20th century religion, if Wiccan paganism is the traditional religion of the family, the religion is considered to be in the blood unless that person chooses to practice a different faith and a practitioner of the faith. Her father, Mr. McKnight, is the owner of the Oakhaven pharmacy.

Physical appearance
In Scooby-Doo and the Witch's Ghost, Thorn is a slender young woman with black hair and red highlights at the roots and ends, pale skin and green eyes. She wears a black and red dress with red sleeves draping down her shoulders,the dress has both legs showing, and has a red sash around her waist. She has black ankle shoes with red tints, red and black fingerless gloves that end at the elbow, and a red bat necklace. Her make-up consists of no eyeshadow with red and black lipstick. She also has red nails.

In Scooby-Doo and the Legend of the Vampire, she wears a dress like her original one, but instead of black it is dark purple, has purple gloves (that don't wrap around the middle finger), and red ankle strap shoes. She still has her red sash around the waist, the bat necklace and the red sleeves at the shoulders, but she has no red streaks in her hair.

Personality
Upon the gang's initial sighting of her, she is shown to be very mysterious and her traditional Wiccan medicinal remedies cause the gang to conclude that she is a witch as traditional folklore describes them. Yet, upon further explanation, Thorn is shown to be quite kind. Thorn is shown to be somewhat unsure of her abilities as a Wiccan, but embraces it with some encouragement from Velma. She grows in courage and confidence following the events of The Witch's Ghost; when Wild Wind attacked her and her bandmates during their concert, she seemed angry rather than scared, telling the vampires that they were "ruining our encore." She didn't seem worse for wear either after being left in the Australian outback for several hours. Thorn also has a sense of humor - albeit a somewhat dark one - and she cares deeply about her father and friends. She has a fascination with the supernatural and all things "spooky" and is also (obviously) interested in music and performing. Thorn apparently has an interest in the natural world and is concerned about preserving the environment, as she describes herself as an "eco-goth". The song she and her band perform at the Autumn Festival, Earth, Wind, Fire and Air, is a further indicator of this.

Scooby-Doo and the Witch's Ghost
After Shaggy Rogers and Scooby-Doo left a local Oakhaven restaurant with their bellies full from overindulging, they see the Hex Girls for the first time in a dark alleyway. They try to impress the girls by pulling in their stomachs and looking handsome but upon getting a closer look at the girls they see that their faces were awfully pale and they had fangs too. Shaggy and Scooby, scared out of their wits, took off fast, while Thorn and the other girls laugh.

Thorn is then seen rehearsing with her band for their big show which they perform the next day, with Ben Ravencroft and the gang watching them and being very impressed. Thorn even managed to mesmerize Fred Jones with her beauty during her performance, and the latter is literally put into a trance until Daphne Blake nudges him. After the performance, Thorn introduces herself and her friends to Ben and the gang, and says that she has always wanted to meet the former. Then she tells them that it was nice meeting them but they had to get back to their rehearsal. The gang are pretty suspicious of the Hex Girls so Fred and Daphne decide to follow Thorn back to her place. They see her in a shed standing over a table with plants and herbs. She mixes some ingredients into a bowl, pours in a weird liquid, and then lifts the bowl, breathing the potion deeply. Daphne is then convinced that she's a witch.

Later, Thorn, Dusk and Luna are then asked to meet Ben and the gang in the woods. The Witch's Ghost appears and shoots a fireball at them which sends them fleeing. After being hit by a large tree branch into a soccer net courtesy of Fred and Daphne, the Witch's Ghost is unmasked and revealed to be Mr. McKnight, the "T-shirt guy". Thorn is shocked by this, and it turns out that the "ghost" was her father all along and her real name is revealed to be Sally. Thorn's dad explains that he and the townsfolk came up with The Witch's Ghost to bring in tourists, which was good for business. Later, at Ben Ravencroft's house, Fred and Daphne apologize to the Hex Girls for thinking that they were witches. The girls tell them they just pretend that stuff and it's just a gimmick for their band. Luna says that they are eco-goths which are similar to Wiccans. Thorn then reveals that that she is 1/16th Wiccan on her mother's side, and the ritual that Fred and Daphne saw her perform was just peppermint and cloves to soothe her vocal cords.

Thorn and the other two girls go with Scooby and the gang to where Scooby found the shoe buckle from before. She is surprised along with the others when Ben reveals that Sarah Ravencroft was in fact a real witch, not a Wiccan. She witnesses Ben becoming a warlock and tries to help her father when he and and the mayor get captured, but she along with the other Hex Girls get bound with magic ropes and tied to a post by Ben.

After the ghost of Sarah Ravencroft was freed from her spell book, she reveals that only a "virtuous soul can imprison her". Seeing Thorn as their only hope to imprison Sarah Ravencroft since she has Wiccan blood in her, Velma Dinkley unties the Hex Girls from their post and asks for Thorn's help. Thorn refuses at first, saying that they don't even have the book, but then Scooby and Shaggy run towards the gang with the spell book. After a series of passes to each of the gang members, the book finally reaches Velma and Thorn. Velma urges Thorn to quickly read the spell. Hurriedly, she reads the spell and finishes just as the Witch's fingers grab the book. The spell had worked, it weakens the Witch and knocks her backward from the force of the spell. However just before it sucks her in, Sarah grabs Ben and drags her in with her. The movie ends with the Hex Girls performing for the audience in the Oakhaven Autumn Fest along with the gang.

Scooby-Doo! And The Legend Of The Vampire
When the gang hears some familiar tunes playing in the background, they go to investigate and find the Hex Girls performing their song "Hex Girl" before Thorn notices them and goes to greet them. The Hex Girls are opening the Vampire Rock Music Festival and are asked if they've seen anything strange since they arrived. Daniel and Russell then come check up on the girls since they were wondering why the music stopped and wanted to make sure that they were alright. Thorn then introduces the gang to Daniel and Russell, saying that they are her friends from America. Daniel tells them that they were afraid of them being bandnapped like Wildwind, who performed in the Vampire Rock Music Festival the previous year. Russell shows the group a poster of Wild Wind and The Hex Girls are very impressed by their make-up and costumes. Thorn speculates that the poster must be from a long time ago, but Daniel tells her that the members of Wildwind are only a couple of years older than them. The locals believe that they've been turned into vampires by the Yowie Yahoo. Fred then thinks that the best way to investigate the mystery is for the gang to go undercover as a rock band and if they are lucky, the vampires might try to kidnap them next. When Shaggy and Scooby attempt to wriggle out of solving the mystery (again), Thorn and the other girls drag them back and help them and the others look the part. The gang was then seen practicing in goofy-looking costumes and playing weird, out-of-shape instruments.

Thorn was then kidnapped along with her band by the Yowie Yahoo and his vampire minions during the middle of their opening performance. They uselessly struggle to free themselves and they disappear along with their captors in a giant puff of smoke. Thorn then appears to the gang near the end of the film telling them not to worry and that she and the girls are fine. When asked how they found their way back, Thorn explains that they were taken to the vampires' hideout in Vampire Rock and were offered free diving trips if they agreed to leave the festival. They refused and were left alone in the outback. They wandered around the outback for hours until Malcolm found them. The Hex Girls then appear at the end of the movie as back-up vocalists in Velma's performance.