One of the longest ever MLP fanfics is getting the MST3K riff treatment from CartsBeforeHorses and Prince Solstice!

Fallout: Equestria! Riffed with permission from Kkat. Thanks, Kkat!
This story is unpublished so that I don't violate FimFiction's rule against published riffs.

Part of the Carts' Unicorn Theater canon. Check that out too, if you want.

THEME SONG:
In the not too distant future, in Twilight's library
Carts invited Solstice over to smoke a bowl of weed
But they were interrupted by Pinkie Pie
She had a devious look in her eye
She locked them up with their bongs
And made them riff a fanfic that's 600,000 words long!

"I'll send them this long fanfic
The longest I can find
They'll have to sit and read it all,
and I'll monitor their minds!"

Now keep in mind Carts can't control
where the fic begins or ends
He'll have to keep his sanity with the help of his pony friends!

Pony rollcall!
Twilight! "Hello."
The Dude! "You're not wrong, you're just an asshole."
Prince Solstice! "Weed."
GROOOOW!

If you're wondering how they can survive
And not die of lung cancer
Just repeat to yourself it's just a fic
In a fictional pony world!

In Mystery Fallout Theater: 3,000!