Cleo and Melody Carver develop a feud that starts with Melody bumping into Cleo in the cafeteria, and hits its peak when Cleo kisses Jackson to spite Melody, to which Melody responds by asking Deuce to the Monster Mash. Somewhere in the beginning of the book, Deuce explains that there was no romance involved at the dance, and gives Cleo a snake, Hissette, which was his mom's first gray hair. He entwines the snake around her wrist and turns it to stone, creating a bracelet. Cleo ends up being one of the few monsters totally against human-monster equality. She especially turns against the crusade when she's offered a photoshoot for Teen Vogue, which she gets her friends involved with as well, and it ends up on the same day as Brett's video shoot for the Ghoul Next Door, a film designed to show the RAD's true nature. She forms a shaky alliance with Bekka, and then backstabs her once she believes the video is deleted. She goes to her photoshoot, which somehow ends up with her, Melody, and Candace, and then learns that the film was sabotaged and uncensored, then aired. She ends up taking the blame by most of her friends. Cleo clears her name at an R.I.P., and ends up being one of the few families to stay in town. She and Melody find a common hatred in Bekka and become friends, and together set up and plan Clawdeen's Sassy Sixteen party, which ends up a huge success when she flaunts her RAD status along with everyone else. When a competition arises for a couple to be named sponsor of a nationwide contest that will donate a million dollars to a school, her and Deuce enter and find fierce competition in Frankie and Brett. Cleo rears her ruthless once more and would have won, had not Billy Phaiden switched the ballots. In the end, her and Frankie make up and salvaged their relationship.
Having gone shopping shortly before Ghoulish Literature, Cleo brings her purchases to class. This draws the attention of Venus, who does not approve of taking bags from the stores and unnecessarily burdening the planet. She tries to convince Cleo to take a reusable shopping bag with her from now, but only manages to irritate the mummy. The situation quickly escalates, both sides unwilling to budge, and Venus loses control. She hits Cleo with a pollen cloud, mind-controlling her into getting herself one solid shopping bag to use. Unable to resist, Cleo enthusiastically agrees, but her anger from before remains. A few days later, like almost everyone else at Monster High, Cleo has come under Sylphia Flapper's mind control and is not freed until a few days later by the efforts of Venus, Rochelle, Robecca, and Cy.
Hopes and Screams
Cleo has to decline writing for the Gory Gazette, but she promises to throw a premiere party in honor of the new issue. She informs Deuce they'll need to find matching ensembles, but she is cut short when his snakes start loudly hissing at her. Deuce and Cleo are send to Bloodgood's office for disrupting Mad Science, but Deuce remains unable to calm his snakes or explain their behavior. He quickly runs off and Cleo, worried she might have to compete with his hair over his affections, follows him. Cleo spots him talking with Frankie in the creepateria and assumes he is following his hair's wishes and replacing her with Frankie. Broken, she returns home and lets Ghoulia comfort her. Going through a book on snakes, Ghoulia finds a possible solution: Cleo has to learn to play the flute in order to charm the snakes. Cleo doesn't hestitate for a moment and signs up for a rush lesson. Once she's ready, she invites Deuce to the clawditorium, where he stumbles over himself to explain that he never would break up with her. The reason his snakes got hostile was because he was preparing an anniversary gift for her and they didn't want him near her for fear he'd spoil the surprise. He gives her the earrings he bought and, flustered, Cleo tells him about her flute lessons. Deuce tells her to play it for him anyway as her own gift, which she gladly does. Cleo and Deuce are awarded a Scream in the latest entry of Clawdeen's Gory Gazette vlog Fashion Screams and Yawns and later shares a tough practice ferleading practice session before the casketball game with her.
I Only Have Eye for You
Cleo goes shopping with Frankie and Ghoulia, she finds a very expensive dress. She's about to buy it but her wallet is short. Cleo goes to her father and demands an advance in her allowance. He is about to comply until Nefera informs their father that Cleo will spend their money on her dates with Deuce. Ramses then reminds Cleo he has never approved of Deuce and he would not pay for their dates. Cleo states that she loves Deuce and they'd be happy together regardless of Ramses' approval. Ramses then cuts her allowance completely.
Deuce later surprises Cleo with a dozen fluffily friends, which makes her happy. It puts a damper in her plans when he said he spent all his money on the fluffy friends, she is disappointed but not angry. Since neither have allowances for the weekend she declares they'll skip the dance. Deuce is fine with this plan and they spend the weekend hanging out at his house. Cleo plays video-games, and wins, and enjoys the dinner Deuce cooks for them. Deuce says he can always depend on Cleo to be resourceful. Cleo states that they will go to the dance, she'll wear an old dress.
Cleo and Deuce go to the dance and are the center of attention. Valentine appears to Draculaura and is threatened by Cleo to prove his innocent claims. He admits to bothering many of the couples before the dance that week. His interference with Cleo& Deuce was calling Cleo's father and offending him in Deuce's honor.