The Headless Horse

The Headless Horse is a horse-like creature and the eponymous character of the ghost story The Legend of The Headless Horse. It is alluded to in the episodes Look Before You Sleep, Sleepless in Ponyville, and Scare Master and other media.

Design and gender
The Headless Horse's build is similar to those of Princess Luna, Fleur Dis Lee, Princess Cadance, the Mane-iac, "Tropical Dream", and Sassy Saddles. Though its body is that of a mare, The Headless Horse is consistently referred to with gender-neutral pronouns.

Depiction in the series
The Headless Horse is first mentioned in the season one episode Look Before You Sleep. During Twilight Sparkle's slumber party at the Golden Oak Library, she tells the Headless Horse story to Applejack and Rarity, and she scares them by briefly impersonating The Headless Horse itself.

"It was a dark and stormy night, just like this one. And three ponies were having a slumber party, just like this one... [...] ...and just when the last pony thought she was safe, there, standing right behind her, just inches away was -- The Headless Horse!"

- Twilight Sparkle

In the season three episode Sleepless in Ponyville, Rainbow Dash tells the story of The Headless Horse to Applejack, Rarity, Apple Bloom, Sweetie Belle, and Scootaloo during a camping trip. Applejack interrupts the story at least twice to comment on The Headless Horse's lack of eyes and brain. The Headless Horse subsequently appears in Scootaloo's nightmares, resembling Princess Luna.

"I've been told that these very woods are haunted... by The Headless Horse! It gallops only at night... [...] ...looking for little lost ponies... [...] Fear was dripping from the air... [...] ...and they were never heard from ever again!"

- Rainbow Dash

In the season five episode Scare Master, Rarity briefly considers Fluttershy dressing up as a "headless pony" for Nightmare Night.

IDW comics
On page 5 of the mini-comic The Fall of Sunset Shimmer, a book titled The Headless Horse is visible on a shelf in a dark magic library in Canterlot Castle.

Chapter books
In Applejack and the Honest-to-Goodness Switcheroo, Applejack briefly recalls the events of Sleepless in Ponyville and remembers the story of The Headless Horse.