It was dark, and empty, and there was no ground. Fog glowed faintly in a light with no source. There was nopony around.
“Hello?” called Pinkie Pie. It didn’t even echo.
Pinkie shivered. Where was everypony? Had… had they left her behind? Was she alone?
Pinkie jumped. “Who said that?”
You did. The words thrummed with power and malevolence. They seemed to arrive right in her head without passing through her ears.
“I did?” Pinkie sat on her haunches and frowned. “That’s funny. I don’t remember saying that. It didn’t even sound like me!”
That’s because it was me. The void seemed to bend weirdly and gain substance, and then Pinkie Pie — another Pinkie Pie — materialised. And I am you.
Pinkie gasped. “Oooh. How did you do that?”
The other Pinkie ignored the question. Her mane and tail hung down limply, and her coat seemed just a few shades too dark. Our friends have abandoned us, Pinkie. Her lips didn’t move as she talked. They don’t like us anymore. They never liked us. Now we’re all alone again. Just you… and me…
“You’re my inner demon, aren’t you?”
What? The other Pinkie recoiled, her face twisted with confusion. How did you know that?
“Because I’ve been getting a doozy of a wiggle in my hoofsies!” Pinkie wobbled her legs in demonstration.
That makes no… Listen. The strange mare resumed her predatory glare and began circling Pinkie. Yes, I am your inner demon. I know you. I know you better than you know yourself. And your so-called friends? They don’t know you at all. They think you’re just silly Pinkie, kooky Pinkie, crazy Pinkie. Annoying Pinkie.
“I don’t think I like you, Inner Demon Pinkie. I don’t wanna be your friend.”
The other mare stumbled. What? What has that got to do with anything?
Pinkie grinned. “Everything! Guess you don’t know me that well, huh?”
“Wait!” Pinkie sat up straight. Her ears perked up and her eyes opened wide. “I just thought of something! Do inner demons count as ghosties?”
The demon glared at her. No. Don’t you even start.
Pinkie put a hoof to her muzzle, trying to contain a snort, but it started to grow bigger and bigger. “Sorry! I just… hehehe… I just can’t help it! You think you’re so dark and spooky! And your mane… Your mane! Haha! You look so funny!”
No! Stop it! I don’t look funny!
Pinkie just giggled harder, until she lost balance and fell onto her side. She rolled around on the lack-of-a-floor. The other Pinkie’s eyes bulged. Stop it! Stop laughing! You’re alone! Everypony hates you! Uh… Your family are dead! There will never be another rainbow! Nothing’s funny! STOP!
“HA!” shouted Pinkie as she awoke.
I knew that I’d get at least one Pinkamena submission for this prompt, and lo and behold. This was a really good submission, and an neat take on the prompt. Pinkie giggling at the ghosties as she is typically want to do was cute, too. Good job!