Meteora Butterfly/History

Star vs the Forces of Evil
As the headmistress of St. Olga's Reform School for Wayward Princesses, Miss Heinous makes sure her staff has the princesses attending her reform school reformed into "normal" princesses. For particularly troublesome princesses, she uses the "Solitary Conform-ment Chamber", which forcibly brainwashes them into acting the way she wants them to.

Despite her best attempts, Star Butterfly and Marco Diaz infiltrate the school and cause a revolt. After they leave, she finds out via experimenting with a bobby pin Marco dropped that they came from Earth, and swears to annihilate them.

In "Goblin Dogs", Pony Head reveals that Miss Heinous has left St. Olga's.

In "Gift of the Card", Miss Heinous is seen living with her assistant Gemini in a rundown apartment complex, with very little money. She hires Rasticore Chaosus Disastervaine to find and destroy Star and bring Marco to her as revenge for what they did to her. However, Rasticore fails, and his forearm is delivered back to Miss Heinous, to her displeasure.

In "Heinous", she, along with Gemini and Rasticore's slowly regenerating arm, comes to the Diaz Household, informing Marco's parents that he has wronged her. After a brief negotiation, she is able to convince them to allow her to punish him by filming a video for the rebel princesses Marco inspired where he renounces the words he used to incite the revolt. Despite Marco saying this in a deeply sarcastic way, Heinous is satisfied with the results and departs. That night, as she prepares to sleep inside her car, she talks to Rasticore's arm, telling it she will annihilate Marco and Star, and make the multiverse "shiver in fear" of her. As she says this, she removes the makeup used to hide her cheek symbols.

In "Princess Turdina", Miss Heinous returns to the school in an effort to get control back. She reveals to her former students that the "Princess Marco" they idolize is a boy, and she also says she needs them just as much as they need her. However, the students chase her off once again, and she starts using princesses as fuel to restore her youth.

In "Monster Bash", Miss Heinous tries to steal Marco's youth, but ends up becoming part of a conflict between Star and Mina Loveberry, during which she is revealed to be Meteora Butterfly, the half-breed daughter of Queen Eclipsa and her monster lover Globgor. In "Total Eclipsa the Moon" and "Butterfly Trap", it is further revealed that she was replaced by the peasant girl Festivia as Eclipsa's daughter and heir after her mother was imprisoned, and all evidence of her existence was erased from royal records.

In "Skooled!", Meteora once again invades the school, this time to discover what happened to her when she was a baby. After confronting and destroying her adoptive mother St. Olga, ripping off Pony Head's horn, tearing out Gemini's robotic heart and blowing up Rasticore's body, she sets out to reclaim the throne of Mewni for herself.

In "Tough Love", Meteora goes on a destructive and soul-stealing rampage across Mewni in her efforts to seize the Mewni throne. Moon and Eclipsa confront her and try to reason with her peacefully, but when that fails, she attacks Moon, leaving her in a vulnerable state, and flees.

In "Divide" and "Conquer", Meteora invades Butterfly Castle in a mad attempt to seize control from acting queen Star Butterfly, eventually succeeding in stealing the souls of everyone on Mewni except Glossaryck, Star, and Tom Lucitor, who is somewhat immune to her soul stealing gaze due to having thousands of them. After a furious battle against Star, Meteora is defeated when her own mother Eclipsa uses the magic wand to revert her back to a baby.

Meteora briefly appears in "Butterfly Follies". crawling around the room Star and Marco are staying. She gives Marco an unnerving glare, leading Marco to nervously wonder if she remembers anything from her former life.

Meteora appears to be teething in "Moon Remembers" as a tooth/fang is shown in her mouth and Glossaryck comments at the rate her teeth are growing as she chews on him.

In "Surviving the Spiderbites", Marco attempts to feed Meteora, only for her to bat away the spoon and bite his hand.

In "Cornball!", Eclipsa brings Meteora to the Mewman/monster cornball game, but Meteora keeps wandering off. At the end, she is seen watching the Mewman and monster kids playing their own game and enjoying it.

In "Meteora's Lesson", Glossaryck takes Meteora back in time in order to help her learn to dip down. When they encounter a younger Toffee (who had broken Glossaryck's arm around that time), Meteora grows angry enough to succeed in dipping down and attacks Toffee. Glossaryck, satisfied with her success, returns them to their proper time.

She is briefly seen during "The Knight Shift", being taught shapes by her mother.

In "Cornonation", Meteora is present for her mother's queen coronation ceremony. When Globgor is revealed to have been released from his prison, suspicion falls on Eclipsa, and Hekapoo imprisons Meteora in a cage. When Globgor appears before the Mewmans and gets into a confrontation with the Magic High Commission, Meteora frees herself from her cage by dipping down, and seeing her helps Globgor calms down.

In "Gone Baby Gone", Meteora accidentally stumbles into Hekapoo's dimension with Marco's baby sister Mariposa, and they grow up into teenagers with a close sisterly bond. When Star and Marco follow them to bring them home, they initially refuse and attempt to trade Star and Marco away to a demonic wish-granter in exchange for giving Mariposa magic powers. After the wish-granter is defeated, Meteora and Mariposa agree to return to Earth when Star and Marco entice them with the offer of food, and they revert back to infants.

In "Ready, Aim, Fire", Meteora shows concern for her father after he is wounded by a Solarian blade.

In "Cleaved", Meteora helps Star, Moon, and Eclipsa destroy all magic in the universe. After her family is reunited once more, Eclipsa decides to enroll Meteora in kindergarten.