During a recent accident, Pinkie Pie was forced to go to the hospital where she was exposed to X-Rays...she then discovered she was more than a normal mare. She was part mare....and part skeleton. A skeleton mare! Twilight seems convinced that she's just a regular mare, or at least as normal as Pinkie could be.

Pinkie Pie analyzes the mental health of oatmeal.

Pinkie Pie loves Nightmare Night. She loves dressing up, and she loves candy. Most of all, she loves pranking ponies. One year she goes too far.

Reading by CaptainBron3y: Pinkie Pie's Last Nightmare Night
Reading by Jennabun (PegasisterReacts): Pinkie Pie's Last Nightmare Night
Reading by AShadowOfCygnus: Pinkie Pie's Last Nightmare Night

Translation into Russian by Dark Room Collaboration

There's an old saying that curiosity killed the cat, and that some mysteries are better left unsolved. What will happen if Pinkie Pie finds a calculator and decides it was a good idea to divide a number by zero? Everything.

What if one day, you woke to see,
Your hair was not what seemed to be?
Would you panic? Would you screech?
In Pinkie's case, yes to each.

Pinkie's mane is not so cute,
For on her scalp, something took root,
Fearing for life and to make things right,
She seeks the help of Ms. Twilight.

What will ensue and how will it end?
Just take a seat and read, my friend.
Hope you enjoy with all my heart,
Because writing this, headaches took part.

Pinkie Pie manages to get some rocks to sing.

Twilight's relentless study of Pinkie's strange abilities leads to a horrifying revelation.

This site really needs an existential horror tag.

Pinkie was always curious to see what Twilight's world looked like...

The challenge in Too Many Pinkie Pies has traumatized Pinkie.
The Challenge: What is going through Pinkie's mind during and after the challenge.
The Nightmare: Pinkie has recurring nightmares of Twilight.

POV of the Pinkie we are lead to believe to be the real Pinkie Pie.
I got the idea some time after watching Reviewing is Magic 5. (Watch it, it'll help explain some things, and get you into the proper mindset)
Tragedy tag is for Pinkie being emotionally scarred by Twilight.
Gore tag is just to be safe.

This is the first time I've written something like this. Tell me what you think, and any questions.
Written in the space of about 2 hours. My own head canon of the events that transpired.
WARNING: Twilight is put in a darker light.

Okay, I don't know if anyone can hear this, or read this, or whatever, but I'm trying my best to use Pinkie Pie's legendary fourth-wall-breaking powers to try and get a message out.

If you can hear this, I need help. I'm in Equestria, and man, this is strange. But I'm also stuck in Pinkie Pie's body, for some reason.

Yes, it's just as weird as it sounds. And now, I need your help... because all the ponies in this town think I'm crazy!