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

The star system Omega Centauri was just another oddity on a map to scientists in the not too distant future. However when they found the star was orbiting an earth-sized, earth-like planet instead of a black hole as its motion had suggested, a mission was scrambled to investigate this most unusual of celestial behaviors.

Hamstrung by politics, and nearly crippled before it began, the 'Lone Ranger' mission was reduced to just one crew member and left to his own devices.

These are the logs of Arrow 18 and its lone commander. This information is classified TOP SECRET by the Global Space Agency.

Do NOT tell the princess.

Princess Celestia tires of constantly being surrounded by decorum, deference, and formality, and decides to take a day off from being Princess. But visiting Ponyville incognito is harder than she expects. Will she be able to fit in and make friends without blowing her cover?

After losing her hive, Queen Chrysalis is forced to start another one. Luckily she has the help of a few loyal subjects who never accepted their fellow changelings new way of life. They must stay hidden from enemies, collect enough food to survive and rebuild their strength. Now the first brood has hatched and there is something very different about one of the larva.

This story is a sequel to What if: Rarity from The Three Sisters met with Chrysalis

Choosing whether or not to visit Chrysalis has been bugging Rarity for a week since receiving an invitation to do so. But there seems to be trouble brewing in the Hive and Rarity now has little time to act. Either way, her family's future rests in her hooves.

Now with a TV Tropes page! Warning: Will Contain spoilers.

This story is a sequel to The Curiosity of Mr. Disc

No, your eyes are not deceiving you, this is the third part of the Mr. Disc series. The thought experiment goes on when Canterlot High's newest student, Twilight Sparkle has gone missing. This gets the attention of the CIA, and the art teacher gets questioned by one of its agents.

A Friendly Warning: the following story has not been edited. If you can't stand stories like these, you know how to exit this story. If you wished to volunteer to edit this, please PM me.

This story is a sequel to Mr. Disc

Once upon a time a retired art teacher, whose name is Mr. Disc, accidentally stumbled into a land of talking ponies called Equestria. He found out quickly that he was in a world where it was close to his own, where his boss was a Princess, some of his students were ponies and even met himself as a spirit of chaos... After a while, he returns home to find that he was able to keep his powers where he lived happily ever after.

Well... not quite yet.

A huge thank you to SecretBrony01 for proofreading this story.

This story is a sequel to Melody of the Future

Two friends separated by circumstances and eras...

Both return to the same time and place, back to their own world, their old lives.

But both have changed greatly, and they did not return alone. And both carry scars of what happened to them, inside and out.

Can these two pick up the pieces of their old lives, and go back to where they were? Or will they perhaps become something more?

Part of the PWNY-verse.

Edit: New Cover Art by Spitfire-Sos over on Deviant Art! It was a prize from a raffle, and I love it so much!

Harry Potter, after a beating by Dudley and friends wishes he had somewhere safe to go, and starts crawling home. He ends up in Equestria. The young Cutie Mark Crusaders find him. A year later, a Hogwarts owl unleashes the CMC, Harry, and Equestria upon wizarding Britain! And adorable cute magic-wielding ponies upon the rest of the world.

Copyedited by gerandakis. Excellent cover art by Mix-up.
Made Featured Stories starting Ch. 18, Jun 25, 2018!
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Inspired by Dogger807’s hilarious story, “Magic School Days,” here on FiMfiction. While there is humour (and tree-sap) in this story, that is not its only focus.

Wow, Sir Chaos Omega made a TV-Tropes page for the story! Thanks!

Published on the FiMfiction website with the kind forbearance of the copyright owners of My Little Pony (Hasbro) and the Harry Potter series (Scholastic Press).

The timeline for “My Little Pony” is messed up. That is, if you look closely, the order of the shows as aired is out of order of their logical sequence. Evidence: in Swarm of the Century (#10) we see the dresses that Rarity makes in Suited for Success (#14) — so unless Rarity time-travelled, #14 should take place before #10! Also, in The Ticket Master (#3), the other five seem to know Twilight and Spike quite well, yet in Boast Busters (#6) they don’t seem to know Twilight at all.

With careful attention to details such as those, you can put the three years of episodes prior to Princess Twilight Sparkle (#65, Season Four) into a two-year stretch of time. If you work hard enough, you can even squeeze them down to one five-season stretch of Summer to Summer.

I used the two-year seven-part timeline mapped out by deviantart’s tobyandmavisforever (do a Google search for “tobyandmavisforever mlp timeline” as the fastest way to find them). Thus, Harry arrives in Equestria shortly after the Crystal Empire two-part episode, and Twilight and Spike have been in Ponyville just under a year even though the Crystal Empire episodes start the third year of My Little Pony.