As Monster High is about teenagers, obviously it has to reserve a spot for celebrities to idolize. To fill that spot, a number of celebrity backgrounders occasionally show up.
First mentioned in "New Ghoul @ School", Justin Biter is a vampire and pop star. He owes the resurrection of his career to Frankie Stein's father. Because of this, Frankie was able to get him to give a concert at Monster High to apologize to Cleo de Nile, a big Justin Biter fan. Later, Frankie got herself two tickets to a Justin Biter concert in "HooDoo You Like?". She also had tickets to see another of his concerts in "Best Ghoulfriend"; but she had eight that time, so she could take all of her friends.
- Justin Biter is based on Justin Bieber.
The Jaundice Brothers one appearance happened in "Jaundice Brothers". Frankie Stein and her friends entered a contest of radio KBLOOD to get the Jaundice Brothers to play at Monster High's Homecoming Dance. Naturally, they won. The Jaundice Brothers were later mentioned by Draculaura in "New Ghoul @ School" as her former idols.
- The Jaundice Brothers are based on the Jonas Brothers.
Unnamed DJ/DJ Death Breath
In the webisode "Party Planners", Frankie Stein's and Draculaura's friends threw the two a birthday party for which they hired a four-armed DJ. In "New Ghoul @ School", he was confirmed to be a celebrity, though his name remained unknown.
Meanwhile, the Facebook entries of August 2, 2011 and March 15, 2011 make mention of a famous DJ, DJ Death Breath, who occasionally pops up in the neighborhood and who is Holt Hyde's music idol. It is possible he and the four-armed DJ are the same, but such connection is not confirmed.
"Dragonfire is known for his outlandish landscaping and private swim park architecture which often includes Lazy Lizard Rivers, Surf’s Up Wave Parks and monstrously wicked water slides. "
- Paulo Dragonfire may be based on Paolo "Paul" Benedetti.
Kind Campaign founders
For the webisode "Kind: The Shockumentary", Kind Campaign founders Lauren Parsekian and Molly Thompson were monsterfied into water monsters, the blue-haired one being Lauren and the cyan-haired one being Molly. No in-universe names have been provided for these two.
Lauren and Molly visited Monster High on a request from Ghoulia Yelps, who was displeased with the way her female friends were treating each other. The duo got everyone together in the clawatorium and had them enter the kind booth to face the reality of their behavior and their desire to do better. Once this procedure had restored peace at Monster High, Lauren and Molly left, another job well done.
Crescenda Von Hammerstone
Crescenda von Hammerstone is a bull-horned Minotaur and opera singer. She has family in Gnarleston, Louisiana, and presumably grew up in the same or a nearby city. The Phantom of the Opera was her first vocal coach, and despite being a diva, Von Hammerstone is laid-back and casual in daily life. Operetta is a huge fan of hers, and won a meet & greet with Von Hammerstone in "Hickmayleeun".
Queen of Fangland
The Queen of Fangland is the ruler of Fangland, Monster High's version of England. Unlike the real life Queen of England, she is a zombie. Unlike most zombies, she speaks regular English. Clawdia Wolf mentions meeting her in one of her short stories. Unlike most zombies, she appears to speak a regular monster language, which is also a typical human language, unlike the language "Zombie", a series of moans and groans. This was shown was she was shown in a fantasy sequence by Howleen, probably from Clawdia's perspective, when she begged Clawdia to fetch the scepter ball from her scepter like a dog toy-ball again, and even wanted to fetch it like a dog ball herself.
Scarantino is a famous undead movie director with a rapid-fire pattern of speech who appears in Frights, Camera, Action. He is kept alive by a key in his back, which needs to be regularly wound up lest he come to a stop. He is based on Quentin Tarantino.
- "Scary and I know It" by LMFL (Little Monster For Life): "Sexy and I Know It" by LMFAO
- "Ghost & Stuff" by UnDeadMau5: "Ghosts 'n' Stuff" by deadmau5
- "The Undead" by Cobra Scare Ship: "The Album" by Cobra Starship
- "13" by Taylor Swamp: "Fifteen" by Taylor Swift
- "Must Dance" by Ghouly Gaga: "Just Dance" by Lady Gaga
- "The Pursuit of Monsterness" by Kid Acula: "Pursuit of Happiness" by Kid Cudi
- "Moves like Nefera" by Mummy 5: "Moves Like Jagger" by Maroon 5
- "Dynamite" by Tao Coffin: "Dynamite" by Taio Cruz
- "Haunt You Like a Scary Song" by Selena Gloomez: "Love You Like a Love Song" by Selena Gomez
- "Thriller" by Monster Jackson: "Thriller" by Michael Jackson
Circe is a witch and the mother of Casta Fierce. Like her daughter, she can turn others into animals. Like her daughter, she also has green skin. She is the Monster High version of the witch Circe from Greek Mythology.