2917. Pinkie Pie

Pinkie Pie, full name Pinkamena Diane Pie, is an earth pony from Ponyville and one of the main characters of the series. She is often seen hanging out at Sugarcube Corner, whether assisting Mr. and Mrs. Cake at work, or holding parties for various ponies. She writes and performs many songs, and has a toothless baby alligator pet named Gummy. She represents the element of laughter.
Pinkie Pie is an outgoing, energetic pony who loves sweets and often speaks and acts in non sequiturs. She has a fondness of parties and a tendency to throw them on a whim. Pinkie Pie plays many instruments and frequently breaks out into song. She also tends to skip rather than walk like most earth ponies. She is often not taken seriously even by her closest friends, who call her out on her seemingly illogical behavior in Swarm of the Century, among other instances. She is almost always excited, and manages to keep her excitement after winning thirty-five consecutive games of tic-tac-toe against Rarity in Dragonshy, while they wait for Fluttershy to catch up. Rarity adds with disinterest, "best of seventy one?"

Pinkie teaches the other ponies to laugh at their fears in Friendship is Magic, part 2 through an impromptu musical number, and helps Twilight accept things even if she doesn't understand them in Feeling Pinkie Keen. She plays a series of pranks on the residents of Ponyville with Rainbow Dash in Griffon the Brush Off, saying "[she] loves to have fun". Still, she draws the line at pranking Fluttershy because of her extreme sensitivity. She decides to take measures, "Pinkie Pie style", when Gilda lashes out at Fluttershy and makes her cry.

Pinkie shows her insecure and somewhat deranged side in Party of One. After her friends give her flimsy excuses for missing Gummy's "after-birthday" party, she breaks into a fit of paranoia that ends with her abandoning her friends for inanimate objects, pretending they are real. She even has an argument with them, complete with weird spasms. Rainbow Dash forcefully pulls her out of her unhinged party and drags her back to her friends. When she finds out her friends did not abandon her, she promptly returns to her usual cheerful self.

Pinkie Pie's personality is magically altered by Discord in The Return of Harmony, part 1. Pinkie finds herself in a balloon garden filled with laughing balloons. At first, Pinkie enjoys it, calling it "the greatest balloon garden [she's] ever seen". However, one of the balloons latches on to her leg and lands her in a mud puddle, and the atmosphere changes into a menacing one. A bunch of other balloons surround her and laugh, and afterwards Discord appears and tells her that her friends are laughing at her. The balloons, formerly sporting benign, smiley faces, distort themselves into the familiar faces of the main cast, even developing their voices and colors, and close in on Pinkie Pie, still laughing. Pinkie's eyes swirl in a "hypnosis" effect and her coat and mane become much grayer. She becomes moody and grumpy, and gets angered when anypony laughs or shows signs of pleasure, suspecting it's at her expense. Near the end of the next episode, Twilight restores her previous color and demeanor through a "memory spell". Afterwards, she is seen being carried away in a wheelbarrow, giggling and remarking "I turned gray! Can you believe it?"