Maud Pie

Doctor Maudileena Daisy "Maud" Pie, is a female Earth pony and Pinkie Pie's older sister. She's on the spectrum of autism. She also has a pet rock named Boulder.

Maud is often depicted with a blank neutral facial expression, with her eyes half-closed and a dry demeanor that contrasts her more upbeat sister. She has a tendency to talk in a rather monotonous and dry tone of voice. She never smiles except for a few occasions while interacting with her closest friends such as Pinkie Pie, Apple Bloom, Starlight Glimmer & her boyfriend Mudbriar. In addition, Maud is shown to have a deep knowledge of and fascination with rocks. Despite her typically flat demeanor, she deeply loves her sister Pinkie Pie and shows a deep concern for her when her life is put in apparent danger. Despite not sharing Pinkie's interests in throwing surprise parties and making candy, she enjoys doing such activities with Pinkie solely because her sister does.

Maud meets Pinkie Pie in Manehattan to celebrate their yearly "Pie Sisters' Surprise Swap Day", in which they spend the day sightseeing together and exchange gifts at sundown. Throughout her stay in Manehattan, Maud mostly expresses interest in rock-related things, and she briefly demonstrates a talent for ice skating. During the gift exchange, Maud gives Pinkie a cardboard container of cupcake-scented confetti, and she receives a special rock pouch to carry her pet Boulder in. However, when she learns that Pinkie acquired the pouch in exchange for her precious party cannon, Maud returns the pouch to get the cannon back. She also tells Pinkie that no matter what she receives for Pie Sisters' Surprise Swap Day, she'll cherish it as long as it is given out of love.

Maud earns her rocktorate in rock science, as well as the title of "doctor", and considers moving to Ponyville to further her studies. As Pinkie shows her what Ponyville has to offer, Maud befriends Starlight Glimmer and bonds with her over rocks and kite-flying. Despite her sister's overeager meddling, Maud eventually decides to settle in Ponyville, moving into a gem cave near the village. During Sunburst's visit to Ponyville, Maud becomes friends with him due to their shared interest in geology. She later helps him reconcile with Starlight Glimmer when she feels left out during his visit.

Maud introduces Pinkie to her boyfriend Mudbriar. His mannerisms and quirks severely get on Pinkie's nerves, to the point where Pinkie is unable to rationalize how or why Maud likes him. After getting some advice from her other sisters Limestone and Marble, Pinkie puts up with Mudbriar because he makes Maud happy, and the three celebrate Maud's birthday together.

Maud and Mudbriar throw a part for their friends to celebrate the Spring Solstice. During the party, Terramar shows up, asking for help finding his sister Silverstream. During the search, the group encounter a flock of Cockatrices, leading to Mudbriar being turned to stone (which turns Maud on significantly). After Silverstream is found, having tamed a Cockatrice she named "Edith", Maud reluctantly asks for Mudbriar to be restored to normal.

Relatives: Igneous Rock (father) Cloudy Quartz (mother) Limestone Pie (older sister) Pinkie Pie (younger sister) Marble Pie (younger sister) Cheese Sandwich (brother-in-law) Li'l Cheese (nephew) Granny Pie (grandmother) Feldspar Granite Pie (paternal grandfather) Nana Pinkie (nana)