While on-screen she is only introduced as "queen of the changelings", she is named Chrysalis in the episode's script and iTunes and Netflix summaries, as well as in merchandise, including trading cards and the comic book series. The episode's script describes her as "QUEEN CHRYSALIS, a GANGLY BLACK PEGACORN with a gnarled black horn." She and the other changelings were designed by Rebecca Dart, the main character designer for season two. Rebecca was inspired by the work of manga artists Junko Mizuno and Hideshi Hino after reading the name "Chrysalis", and "figured she should be insect-like."
Chrysalis in her Cadance disguise.Added by MysteriousForceQueen Chrysalis first appears impersonating Princess Cadance in A Canterlot Wedding - Part 1, looking and sounding like her, but acting different enough to raise Twilight Sparkle's suspicions, though Twilight's friends, Shining Armor, and Princess Celestia don't buy Twilight's story. Chrysalis walks on-screen right after Twilight's flashback and description of her memory of Cadance as a beautiful, loving, and kind pony, from when she foal-sat Twilight. Chrysalis doesn't recognize Twilight, which unsettles her and raises her suspicions. When Chrysalis comes to check the menu for the wedding, she insists on being called "Princess Mi Amore Cadenza", and even though she politely compliments Applejack on her baking, she throws away the food Applejack offers her, again raising the ire of Twilight. When she comes to inspect the dresses Rarity is sewing for the wedding, she sneers at her bridesmaids who praise the dresses and asks Rarity to make the dresses a different color. She sarcastically remarks on Pinkie Pie's party plans that they're "perfect... if you were celebrating a six-year-old's birthday party." Twilight sums up Chrysalis's behavior to her friends as "an awful pony who doesn't deserve to even know Shining Armor let alone marry him." When Twilight tries to discuss the matter with Shining Armor, Chrysalis interrupts them before Twilight has a chance to say anything; Twilight comments that "she sure has a way of sneaking up on people." Chrysalis asks Shining Armor to go into the other room, where she casts a spell on him that makes his eyes roll. Twilight spies on them through the door and runs out after seeing Chrysalis cast the spell.
At the wedding rehearsal, Twilight accuses Chrysalis of being evil and levies some accusations on her. Chrysalis tears up and and runs away, and Shining Armor confronts Twilight and dispels her accusations, saying "Cadance" is using her magic to heal the migraines he receives from his protection spell. All the ponies leave the room, and after a short reprise of B.B.B.F.F. Chrysalis returns and stomps on the figure of Twilight that's left over from the song. At first she looks down at Twilight with a compassionate face, but then her eyes glow green and engulf Twilight in green flames that sink with her into the ground down to the caves beneath Canterlot.
The next episode, A Canterlot Wedding - Part 2, begins with Chrysalis, still under the guise of Cadance, taunting Twilight through apparitions in an underground cavern's crystals, and telling her that she's using Shining Armor for her own benefit. Twilight shatters the crystals and uncovers a path to the real Cadance, also imprisoned by the changeling queen. A song sequence follows featuring Chrysalis and Cadance singing about the wedding. After outwitting Chrysalis's three bridesmaids who were guarding the cave, Cadance and Twilight manage to confront Chrysalis right before Princess Celestia weds her to Shining Armor.
Princess Cadance proclaims that the impostor is a changeling, a creature that takes the form of those that are loved and gains power by feeding off the love for them. After that, the imposter transforms and introduces herself as queen of the changelings, who is named Chrysalis in the episode's script but not on-screen. She keeps Cadance at bay by threatening to send her back to the caves, and explains that she's been feeding on Shining Armor's love for Cadance, which weakens his protection spell that keeps the changelings out of Canterlot. Princess Celestia confronts her and attacks her with a beam from her horn, but Chrysalis fires back and, thanks to the power of Shining Armor's love, overpowers Celestia and knocks her to the ground, much to the surprise of everyone, including herself. Celestia urges Twilight and her friends to get the Elements of Harmony and use them to defeat the queen. The changelings break through the magical barrier protecting Canterlot and capture Twilight and her friends, bringing them back to the wedding hall, where Celestia finds herself encased in a chrysalis hanging from the ceiling. The queen sends her subjects to feed, and sings a reprise of This Day Aria, which allows Twilight to free Cadance when Chrysalis is distracted. Cadance's magic breaks the spell over Shining Armor, and gives him strength. The Queen mocks this sentiment but quickly finds that Shining Armor's spell repels her and all of the changelings out of Canterlot, flying into the distance.
Queen Chrysalis spends the entirety of A Canterlot Wedding - Part 1 and the beginning of Part 2 disguised as Princess Cadance, with her eyes occasionally flashing green and her magic glowing green instead of Cadance's blue.
After she is confronted by the real Cadance, she transforms into a creature that looks like a pony with a twisted unicorn horn, a pair of tattered insectoid wings, and stands as tall as Princess Celestia. Unlike a pony however, she has a sharp pair of fangs and dark green eyes with elongated oval pupils. She has a teal mane and tail, blue-green chitinous plating over her midsection, and she wears a small, black crown tipped with blue orbs. Her voice has a distorted echoed quality, as if two voices are speaking slightly out of sync. Her legs, mane, and tail are full of holes and her limbs and torso are very slender. Like other non-pony characters, she has no cutie mark.