Pinkamena Diane Pie (Pinkie Pie) is a pink earth pony with light blue eyes and curly, dark pink mane and tail. Her cutie mark is two blue balloons with yellow strings and one yellow balloon with a blue string. she is a baker and confectioner at the Sugarcube Corner and a party planner. She is hyperactive, random and quite silly but is also friendly and uncommonly kind. She enjoys singing, is musically talented, and often suddenly breaks into song, to the confusion of onlookers. She also likes playing pranks, sometimes with Rainbow Dash's help, though she refuses to play any on Fluttershy due to her sensitive nature. Her behavior is frequently random and sometimes chaotic and she has been known to break the fourth wall. The character often smiles.[5] She possesses the "Pinkie Sense", an ability to predict events in the immediate future through twitches of various body parts (For example, whenever her tail twitches, often referred to "Twitchy Tail", it means something will fall, whether from the sky or on the ground), and has a photographic or Eidetic memory.[10] When she becomes sad enough, her mane and tail change from curly to straight and her pink coloration loses its brightness. While she usually hops around, Pinkie is exceptionally quick when running, able to keep pace with airborne Rainbow Dash. She has a toothless pet alligator named Gummy. Pinkie represents the Element of Laughter.

In "The Cutie Mark Chronicles", Pinkie Pie tells the Cutie Mark Crusaders that she was raised in a rock farm with a conservative family. In a flashback sequence, her mother calls her by full name "Pinkamena Diane Pie", and she has straight hair until the wave of Rainbow Dash's Sonic Rainboom caused her hair to curl and thicken, and the accompanying rainbow made her feel happiness and to smile for the first time. The next morning, she throws a party in the family silo and gets her family to smile as well, and earns her cutie mark.[8]