Casta Fierce is a 2014-introduced and all-around character. She is a witch, specifically the daughter of Circe, and the lead singer of The Spells. Aside from Casta, The Spells consist of three girls who are uniquely immune to Casta's magic. Like her mother, Casta can turn anyone into any animal, but she has limited control over her powers. One misspoken word or unfortunately phrased sentence is enough to turn anyone hearing it into the matching animal. This has put a damper on her singing career, but Casta and her band keep making music as they look for solutions. Casta is a close friend of Catty Noir, a colleague of hers.
She is voiced by Erin Fitzgerald in the English dub in the series.
Casta has long black hair with purple and orange highlights on her fringe and green skin. She also has a beauty mark and a painted yellow lightning bolt on her face. Her outfit consists of a sparkly dress that is purple and orange that cascades into a flowing orange and black net with a black belt. She has on spiked purple boots, a fishnet arm warmer, and holds a purple broom with orange ribbons and a purple microphone. Her hair may sometimes be tied up in a ponytail.
Casta is shown to care about her fans, willing to fulfil a request asked of her, by her fans. She is also shown to get embarrassed when she's on stage and says a spell that on accident turns her fans in the crowd into animals. Causing her to have a bit of stage fright as that's all she can think about, but after Toralei Stripe makes a fool of herself, it helps Casta take her mind off things allowing her to preform again.
Casta Fierce is the daughter of Circe the goddess of magic. Like her mother she can also turn people and other monsters into animals. Casta and her mother seem very close as her mother watched her preform at Monster High, and in a flashback to a younger Casta, she is with her mother.
Casta is a close friend of Catty Noir, a fellow but younger singer who has put her career on pause to return to a regular life. Supposedly, Casta also is close with her fellow band members. She is also best friends with Operetta.
- Magic: As a witch, Casta is able to cast spells and perform magic. Her magic manifests as violet orbs and when she used her magic on the potion, her hands glowed.
- Animal Transformation: Like her mother, Casta can turn other people into animals. She has very limited control over this power and can turn other people into animals by saying a misspoken word or phrase. Like all witches, she can also turn other people into animals by casting a spell.
Casta's mother Circe is a well known sorceress from Greco-Roman Mythology (although not the actual Goddess of magic, that would be Hekate who in some stories is Circe's mother). Circe is best known for her role in The Odyssey where she lives on the isolated island of Aeaea where she uses potions to turn the men who visit her into livestock like pigs. She comes to fall in love with the hero Ulysses/Odysseus and even teaches him how to make contact with the dead in the Underworld.
- September 22, 2013: Mattel requests the trademark for Casta Fierce.
- February 14, 2014: Casta Fierce is revealed during the 2014 Mattel Toy Fair Analyst Meeting.
- March 31, 2014: The connection between the trademark and character is confirmed by J.S. Sporting.com's listings.
- May 29, 2014: Casta Fierce's profile is published on the Monster High website and promptly removed.
- May 29, 2014: Casta Fierce's profile art is revealed.
- June 05, 2014: Casta Fierce's profile is re-published on the Monster High website and promptly removed.
- July 24, 2014: Casta Fierce's profile is re-re-published on the Monster High website.
- Late August, 2014: Casta Fierce's debut doll is released as a lone 'Signature' doll.
- The name Casta Fierce is inspired by Sasha Fierce, an onstage alter-ego of Beyoncé. Her hair is even styled the same way as Beyoncé's was in the video clip of "Single Ladies (Put a Ring on It)", which is a song released as part of the I Am... Sasha Fierce album. The Spells are a parody of Beyoncé‘s former band Destiny’s Child.
- Casta's green skin and mole are done to make her resemble the Wicked Witch of the West from MGM's 1939 adaption of the Wizard of Oz. However, MGM holds a copyright on the shade of green skin used and the placement of the mole so both of these were changed in Casta's design (along with making her mole look like more of a beauty-mark). Casta having a broomstick also makes her closer resemble that witch however it was a common folkloric staple of the witch even before the film.
- Fierce is her stage name, her real name is Casta Cauldronello (from Garrett Sander via Instagram stories).