MLP/Undertale crossover.
Not a PWNY-verse story.

Long ago, the Monsters and Humans fought a great war. The Monsters lost, and were sealed in the Underground. It would take the power of seven human souls to break the barrier that kept them imprisoned. They only had six. And so the Monsters waited and hoped, praying that another human would find their way to the Underground. Some thought the seventh soul would give their King the strength to break the barrier. Some dreamed of a human who would be their friend, and save them all...or had nightmares of one who would bring back the war.

...but nobody came.

...but somepony did.

Eons after the war, with no way to tell how much time had passed above, a tiny blue filly with wings and horn fell into the underground, calling for her Mama. None knew the poor creature's nature or origins...but her soul was powerful with magic, even more so than a human soul.

None can know what will come...of this little 'Woona'.

Cover art by Sanyo21

While Applejack automatically tunes out the normal background noises of Sweet Apple Acres, out of place sounds always get her attention, even gentle ones. She notices such a sound while heading back home for supper, and finds Fluttershy in the orchard. The reason for Fluttershy's visit turns out to be one Applejack hadn't thought of.

Cover art by Evehly.
Reviewed on Louder Yay.

One day while Fluttershy as walking in the woods, she found a strange creature. This creature says that her name is Miia (from Everyday life with monster girls). How will Miia get along in a place like Equestria, a land that is always in a positive mood, is like a living musical, and most of all, filled with herbivores. How will the ponies get along with Miia and how she is very different from them. This is a story of her time there.
Teen for language/swearing, and sexual comments.

Pinkie started out friends with Fluttershy but after seeing her best friend crying she goes all out to make her happier. A long few days lead to a relationship no pony could have expected in ways most memorable.

Complete; sequel here

Pinkie Pie invites the gang to a sleepover. Everyone except Fluttershy doesn't shows up. Will Fluttershy's feelings escape or will she be able to withstand the night with the pink pony? What could go wrong!

Except everything...

I'm now supporting FlutterPie/PinkieShy! When did this happen?

It is recommended you read this story in one of the Dark formats in order to better distinguish the colored text of the 'other voices'.

Hey folks! Name's Deadpool!
I thought that was all of us?
It is. He's just introducing us as a single entity.
Will you two idiots be quiet? I'm trying to talk to the readers! Anyway, I know you've all been waiting with bated breath for this story ever since it was announced, and here it is! And it's going to have everything you'd expect of such a story!
Explosions!
Adorable father-daughter bonding moments.
Total babes!
Awkward hilarity.
Not to mention me, Deadpool, the merc with-
Daddy, who are you talking to?
Oh hey Chryssi! Just telling the readers about-
Are you breaking the fourth wall again? I thought you were going to teach me how to do that today.
That's what I'm doing! Say hi to the readers, Chryssi!
You will all love me and despair as I feed upon your adoration to become an unstoppable god!
That's my girl! Hey, wanna read the story with me?
I brought popcorn and chimichangas.
*sniffle* You're the best thing to ever happen to me, Chryssi!

Hey look! We've got cover art now!
Aww, you were so cute at that age!
And I'm not cute now?
Now you're sexy!
We should thank Sanyo21 for the image.
Then I guess I'll throw up a link! Nnnghha! http://www.fimfiction.net/user/sanyo21
...did you really have to literally throw it?
Yup!
Oh, and for those who don't know yet, this story is part of the PWNY-verse. It's not all about us - even if it should be - but you'll probably enjoy it to-Oh, stop making me a shill already!

Oh, by the way, it's recommended you read this story in Dark or Ultra Dark. Some of the colored text doesn't show up clearly otherwise. Not necessary, but just a suggestion.

Jak never found it unusual that he had a unicorn brother. Shining Armor had been there his entire life, as far as he could remember. Sure, Daxter often made a point of just how strange it was relative to everyone else in the village, but then again Jak himself was different from the rest of the villagers.

He never questioned that he looked somewhat different from everyone else. Never questioned that he was raised by Samos the Sage, alongside Samos' daughter Keira, whom he kinda-sorta liked and who kinda-sorta liked him, even if Samos himself didn't like that. Jak, by nature, wasn't the sort to question things.

Shining Armor, on the other hand - or hoof - had lots of questions, but no answers.

...yet.

Part of the PWNY-verse.

Crossover idea suggested by Keyblade Hero.
Cover art by Sanyo21

Tony Stark had everything he wanted in his life. He had his company. He had a carefree life where he could simply enjoy himself and tinker with whatever came to mind...and he was a super hero to boot! He couldn't imagine ever being happier.

And then a rainbow-maned Pegasus foal dropped into his life, and turned it upside down.

Lucky for Tony Stark that the multiverse is much more imaginative than he is.

Part of the PWNY-verse.

Will freely mix several different Iron Man continuities based on what makes the story work best.

After capturing Sombra, there is little consensus on what to do next. They turn to Equestria's resident villain reformation expert, Fluttershy to be an arbitrator. To reform or not? If only the decision were that simple . . .

Inspired by wonderdania's comic on deviantart. Used as cover art with permission. Thanks for getting me hooked on this ship! I love it.

Pre-reading by Darkwolfthelycan and my good buddy, Miranda Laufeyson.

After the events of the Battle of the Bands, Adagio and Sonata have gotten over their loss of power and are building lives for themselves. Aria however, hasn't accepted the failure. When she is cast out by the other Sirens, she finds herself living with Fluttershy.

A fic exchange thing with MythrilMoth