Meredy is a character who appears in the anime Fairy Tail (2014) as a member of the dark guild Grimoire Heart and one of its seven most powerful mages, known as the Seven Kin of Purgatory. Her background begins with tragedy: her hometown was destroyed by three members of Grimoire Heart, including Ultear Milkovich. After the attack, Ultear took the orphaned Meredy into the guild out of sympathy for her own difficult childhood, sensing great magical potential in the girl. Meredy was raised by the guild master Hades and trained in the Lost Magic known as Maguilty Sense. She came to view Ultear as a surrogate mother, forming a deep emotional bond with her. She remained unaware that Ultear was responsible for her hometown's destruction.

As a young girl during the Tenrou Island arc, Meredy is short with pink hair and green eyes, wearing a purple leotard, thigh-high boots, a red cape with a gold lining, and gold wing-like headgear. She presents a stoic, mature, and calm demeanor to her enemies. Her speech is often robotic and measured, and she refers to her mission of extermination as the prime directive. She assigns numbers to her targets, intending to kill them in a specific order, with Gray Fullbuster ranked first because she blames him for Ultear's injuries. In battle, she can seem cocky and refers to weaker opponents as trash. However, her true personality is more childlike and vulnerable. On the airship approaching Tenrou Island, she shows excitement and curiosity, and she becomes ashamed when Ultear scolds her. She also demonstrates immense passion and resolve, willing to sacrifice herself for the one she loves.

Her primary motivation during her early appearance is to serve Grimoire Heart's goal of awakening Zeref to create a world where only mages thrive, and more personally, to avenge Ultear by killing Gray Fullbuster. She enters combat against Erza Scarlet and Juvia Lockser on Tenrou Island. Her magical ability, Maguilty Sense, allows her to link the senses of two or more people, causing pain or sensations to be shared. She uses this magic to connect Gray and Juvia, ensuring that any harm done to Juvia affects Gray. When Juvia refuses to kill her and instead embraces her, Meredy's emotions are reached through their sensory link. Juvia sees Meredy's memories and begs her to live for the people she loves rather than throw her life away. This moment changes Meredy. She stops fighting and later carries the weakened Juvia to safety when the island's magic is drained.

After the seven-year time skip, Meredy has grown into a taller, older, and more cheerful individual. She becomes a member and co-founder of the independent guild Crime Sorcière, a group dedicated to atoning for past sins and opposing dark forces. Her demeanor becomes much happier, modest, and playful. She develops a witty sense of humor, teasing Gray and Lucy with her sensory link magic and joking with Jellal about his lies. She reunites with Juvia at the Grand Magic Games and greets her kindly with a smile. Her role in the story expands as she uses her magic to sense powerful presences and assist Crime Sorcière in their mission. She also uses her Maguilty Sense later to connect the senses of many mages across the continent to pool their magic to support a protective spell against Acnologia. Her key relationships include her deep bond with Ultear, who remains the most important person in her life, and a new friendship with Juvia, who taught her the value of living for others. She also interacts with other members of Crime Sorcière, such as Jellal and Erik. Her development transforms her from a cold, duty-bound assassin into a compassionate, light-hearted ally who fights to protect others.