Mixolydia is one of the seven Magypsies of Mother 3. She lives on Tanetane Island. While Lucas, Duster and Kumatora are hallucinating, she looks more feminine than any of the Magypsies. She is known to cure travelers who have eaten mushrooms native to the island which cause powerful hallucinations and pick at the scars of a person's heart (a person's inner weaknesses). She does this by using a 2x4 and bashing them upside the head, knocking the sense back into the mushroom victim. She has a pet octopus named Ocho who serves as a taxi and combs the beaches of the island. During the hallucinations of the party he appears to be a butler mopping the floor.

Unfortunately, she has vanished because by the time the party defeats the rough-and-tumble Barrier Trio, the Masked Man appears, strikes the party down with lighting, and pulls the needle. Like the other Magypsies, she couldn't feel the heart of the Masked Man. She gives Lucas the Jar of Yummy Pickles, and then vanishes, leaving an item called "Missy's Memento".

After she vanishes, her house is inhabited by magic butterflies.