OC's are pretty huge in fanfics too! We haven't really coralled these up before. Expect lots of unique stories starring lots of unique ponies!
Get them all below. Thanks to Whisper Key for gathering them.
Slice of Life
The Casebook of Currycombs by AugieDog
https://www.fimfiction.net/
Through a long-forgotten mirror buried deep within Starswirl the Bearded's laboratory lies the equine kingdom of Hevosenvalta. There, the unicorn medical mare Silver Scalpel has just received an honorable discharge from Her Majesty's cavalry due to injuries she sustained on the frontier. She finds herself at loose ends in the capital city of Ehwazton until a chance encounter with the aardhorse detective Currycombs changes both their lives forever.
Just a Little Batty by I Thought I Was Toast
https://www.fimfiction.net/
The first day of school always sucks. It's particularly sucky when you're normally nocturnal.
Stars Above by Novel-Idea
https://www.fimfiction.net/
On her very first trip above the clouds at night, the young Blue Venture finds something she never expected.
Herself.
An Earth Pony Orphan In The Unicorn Court by Benman
https://www.fimfiction.net/
In the time before the three pony tribes became one, a rampaging monster tears apart a noble caravan. Now the baron’s shattered family must put itself back together—with one remarkable addition.
Coming Home by Noble Thought
https://www.fimfiction.net/
Marian, a recent graduate from the prestigious Manehattan School of Library Sciences, returns home to Dodge Junction to found a library. To do so, she must face the sister she ran away from after making a terrible mistake.
Her sister, Cherish, who holds the keys to her dream.
Einherjar by Municipal Engines
https://www.fimfiction.net/
The Glorious Thousand were the ones who stayed. They were the ones who fought. They were the ones who died so that others may live. This was their final moment of respite, in the face of certain death. Here they waited, at the end of it all.
The One Who Got Away by Georg
https://www.fimfiction.net/
When Gaberdine is awarded a noble title by Princess Celestia, he soon finds out that his new lands contain several surprises. For starters, there is no land in his new barony. Secondly, his new castle turns out to be a broken-down riverboat. And third is… seaponies.
Baron Gaberdine has a lot to learn about his new barony. And himself.
Fortunately, he has a very young teacher.
Comedy
The Adventures of Batsy Fluffentuft the Magnificent by ocalhoun
https://www.fimfiction.net/
Batsy Fluffentuft (not the most respected of the lunar guards, and in fact on super-probation from Princess Luna herself) manages to escape into the town of Canterlot and have herself an adventure.
Agent Redwood by DannyJ
https://www.fimfiction.net/
Redwood is a mare of simple desires. She enjoys alcohol, male company, and competitive challenges, and is best known for her uncanny ability to find all three wherever she goes. What she is not known for is her discipline and restraint.
Perhaps a military career was not a smart choice for her.
This is a Stick-Up by Georg
https://www.fimfiction.net/
Many years ago, Ponyville was even smaller than it is now. But not too small to experience its first bank robbery.
In distinctly Ponyville style.
Mailed Male Changeling Chainmail Exchange by Raugos
https://www.fimfiction.net/
They say that good armour is a Royal Guard's best friend.
Sometimes, it might be a little more literal than expected.
After all, it isn’t every day that one receives shameless self-promotion from their protective attire.
Swine Flew by Blue Print
https://www.fimfiction.net/
Porkmetheus is an exceptional pig, and Ponyville's most energetic porcine resident. After an accident sparks his tiny imagination, he wonders if, maybe, he too could fly!
The Rummy Business of Old Blooey by Cloud Wander
https://www.fimfiction.net/
Barney Trotter and his valet, Cheese, struggle to assist young Prince Blueblood, who has accidentally become engaged to be married. On the night of the Grand Galloping Gala, Barney unfolds a masterful plan to rescue his pal from the harness of matrimony.
A parody of PG Wodehouse's Jeeves & Wooster stories.
Sad/Dark
Where the Cold Comes From by Motorbreath
https://www.fimfiction.net/
A heavy snowstorm traps a group of ponies in a tiny hamlet far away from any civilization, and while the adults are doing their best to fend off the elements and ration the quckly fading supplies, the foals decide to go out of bounds and figure it out on their own. But only one of them will be able to find out where the cold comes from.
Through the Ice by Admiral Biscuit
https://www.fimfiction.net/
The weather forecast promised a snowstorm, and the weatherponies delivered a proper blizzard. Blowing snow, low visibility, not weather any pony would want to be out in.
Buttonwood works at the livery, hauling wagons, and wants to save up enough bits to travel to Prance. Trains wait for nopony; loads must be delivered even on the worst days, and she could stay home but if she does, she’ll never save up enough bits for her trip. She knows the roads, the wagons, the shortcuts. She knows a lot of her co-workers won’t show up in such miserable weather, and that means better loads and more bits. Snow won’t stop a motivated pony.
Away by The Cloptimist
https://www.fimfiction.net/
A unicorn with an unwanted special magical talent isolates herself on a remote hillside, away from other ponies, for their sake and hers.
A Faded Touch of Blue by Tofazz
https://www.fimfiction.net/
Moxie gazed over the stallion in front of her, as the crowd stared at them in turn. Fellow nobles, dignitaries, and her parents had all gathered here, in the balmy mansion of her birth, to witness this occasion. The final words had been said, and they were now officially husband and wife. But she was not happy; this was not her wish.
She ran her hoof down the lock of blue hair entwined in her mane. Her whole life had been decided for her, everything coordinated to the tiniest detail. What she had learnt, how she spent her leisure, who she knew, whose company she enjoyed, whom she had pledged herself to, everything... except the one trip she had taken to Canterlot without the permission of her parents, that is. The glimmering blue strands linger as a testament to her last free action...
All Paths Lead Home by Mystic
https://www.fimfiction.net/
Through fire and fear, and darkness and shadow, when the end of the world came, it came swiftly to the peaceful land of Equestria. Now, almost ten years after this cataclysm, a lone mare and her daughter embark on an epic journey of survival across the wasted Equestrian landscape, trying to find hope and meaning in a world where harmony is nothing but a memory.
Beyond the Wall by Filler
https://www.fimfiction.net/
Never enter the woods alone, for there are monsters there. They can look like anything, even another pony. And if you waver in Gaea's love, you will become one.
Letters from a Senior to a Junior Changeling by Chris
https://www.fimfiction.net/
A series of notes sent to a young changeling in the field by her superior, and a glimpse into the minds of a race whose views on friendship and love are at once totally alien and disturbingly easy to recognize in ourselves and those around us.
Promised Land by Obselescence
https://www.fimfiction.net/
Twilight Sparkle has walked the wastelands for a very long time, but now, at last, he has reached the end of his journey. He only hopes now that the gods will listen to his prayers, and finally allow him a good place to die.
Sugarcube in the Corner by WishyWish
https://www.fimfiction.net/
Enter Painless - a young resident physician at Manehattan East Side Memorial Hospital who drew the short lot, and ended up working through Hearth's Warming. With the city caught in the grips of a blizzard that weatherponies are still trying to get under control, the night is boring, the decorations contrived, and the coffee is as bitter as his sensibilities.
Tonight, Painless has a single, pointless task assigned to him - To keep the company of a lonesome, unconscious stallion who is essentially already dead. In so doing, a young doctor will learn that medicine is about more than scalpels and technique.
It's also about mending broken hearts.
To Be A Mule by archonix
https://www.fimfiction.net/
She smiles at him every time she comes to visit the stately home where he works as a gardener, but Dilly Daliér has never spoken to her.
Nor will he ever.
Because he's a mule and she's a unicorn, and those are the rules.
Two Ponies by TwilightSnarkle
https://www.fimfiction.net/
A look at the life of an average pony, and the exceptional love he had for others.
White Box by chrumsum
https://www.fimfiction.net/
My name is Canvas. I remember because I wrote it in the corner of the white box. It takes twelve steps to get from the cot to the wall. And the lights hurt my eyes.
Shipping
My Farrier Lady, Sunspot by Georg
https://www.fimfiction.net/
Once upon a time, there were two friends who ran a farrier shop in Canterlot. The oldest fed the forge and used his earth pony magic to produce strong steel shoes, which the younger enchanted with his powerful unicorn magic. They worked together in harmony, creating beautiful shoes for all who visited until one day they met a young mare in their local bar. She was a mysterious creature, overstressed by her job in the palace and needing the company of two friends far more than she realized.
Until one night, when her sister returned during the Summer Sun Festival…
Of Flies and Spiders by wYvern
https://www.fimfiction.net/
Glitter was banished from her hive because she's different: instead of feeding on love, she feeds on anger, fear, and sadness. Ponies are easily fooled and more easily manipulated. Staying undetected and sustaining her dietary needs, she goes through life bringing misery to those around her. All changes though when he turns up, tearing down walls built throughout a lifetime.
The Instruments of Our Surrender by Cold in Gardez
https://www.fimfiction.net/
Love can take root in the most unlikely of places.
In Equestria's darkest moment, when Tirek seemed unstoppable, when the princesses lay chained in Tartarus, when the Elements were helpless, two ponies discover that no one is so weak that they cannot fight back. And what matters more than victory is what you discover along the way.
Drama
Heat Death for Two by Comma Typer
https://www.fimfiction.net/
The sun has burned down everything.
Far up north lies the "coldest" place in the world: deathly hot but livable.
A pony traveled here to survive. Now he waits to see the end.
Until an angel bearing the last gift in history visits him.
The Paths Beneath Us by BlazzingInferno
https://www.fimfiction.net/
The deepest gem mines were there before Equestria, and so were the donkeys. Every facet of their way of life, from its trials to its triumphs, have stood unchanged for eons.
Mica knows this. She also knows accidents happen; the last one took her parents. Hopefully she and her twin sister can survive the next.
Unchanging Love by Azure Notion
https://www.fimfiction.net/
It’s the week before the Canterlot wedding and tensions are high, even more so for the changeling love collectors. With the results of the wedding, life is going to change drastically, regardless of the outcome.
For one co-owner of the Sweet Roast Cafe, wife to a loving stallion, and undercover changeling, Sweet Leaf can only hope this change is kind.
In Dreams by OleGrayMane
https://www.fimfiction.net/
IN MOUNTAINS FAR, FAR AWAY, a very long time ago, a young unicorn slept in a dragon’s cave and dreamed.
A fairytale of old Equestria.
Curse, Bless Me Now by Pascoite
https://www.fimfiction.net/
Star Shine is quite a rare colt. In fact, some ponies believe him to be cursed, based on an old mares' tale. Detective Gumshoe doesn't believe a word of it, and if it's the last thing he does, he'll serve the city and the Princesses he loves by finding out what's really been terrorizing the neighborhood.
Adventure
Tough Cookie and Syntax by Blazewing
https://www.fimfiction.net/
Tough Cookie is a plump and sassy artifact appraiser who runs an antique shop in Canterlot. Syntax is a sophisticated bookseller and polyglot who runs a bookstore, also in Canterlot. Though different in disposition, these two friends share a common interest: seeking out rare, historical treasures. This story details one such adventure of theirs.
In the Crystal Crypts by peppermint owl
https://www.fimfiction.net/
Over a thousand years ago, a costly war raged in the north. Its end was marked with a heavy tax imposed on the losing city, one that demanded the minotaurs pay in blood.
Six years pass, and with each year comes a new drawing of lots. On the seventh year, a new name is drawn, and yet another victim is cast into the labyrinth…
Scarlet by Skijarama
https://www.fimfiction.net/
Scarlet Frost has had more than enough death and violence in her life and has spent the last several years living quietly as a librarian and scholar in the New Equestrian city of Swanrun. Sadly, it seems that death and violence are not yet done with her, as she is about to discover.
After a chance encounter, Scarlet is forced to leave her home and flee for her life alongside a mysterious orphan filly named Primrose. Now being hunted across the land she once went to war for, Scarlet will have to use every resource at her disposal just to stay alive. And if she is going to make it through this, she must confront the ghosts of not only her own past, but those of this long-broken world as well.
A Story of Solstice by redsquirrel456
https://www.fimfiction.net/
Long before the reign of the Princesses, life is hard for ponies. A single decision can change, end, or begin a whole new life.
On the night of her child's birth, one pegasus makes the fateful choice to abandon her home for the sake of love, and faces the longest night of her life as the consequences race to meet her below the clouds.
Fallout: Equestria by Kkat
https://www.fimfiction.net/
Fallout. With ponies! Set in an alternate future, one pony must learn to survive in a blasted, poisoned land... and possibly, with the aid of friends made along the way, bring new light into the darkness of post-apocalyptic Equestria.
The War and What Came After by NorsePony
https://www.fimfiction.net/
The earth had belonged to the People since time immemorial, until the ponies came to push them out. For centuries, they have hidden in the forest and the hills, slowly losing ground to their enemies.
But now the gods have chosen two young warriors.
Our First Steps by Mrakoplaz
https://www.fimfiction.net/
„In a secluded desert on the frontiers of Equestria, an eccentric genius works to bring the stars within reach of everypony. But can smiths and metalworkers who never made anything more difficult than ploughs or golden trinkets really make the dream a reality? Or has inspiration arrived a hundred years too early?“