1 - 20 of 224 Works in Alternate Universe - Mobtale (Undertale)
Navigation
Listing Works
-
Tags
Summary
You and your family are just enjoying a nice day at the park, when a life changing event happens that ruins everything.
You get taken away to a facility to be tested on...
Life doesn't feel as peaceful as it once did, you hated your new life.
"I wish I could just go into those story books I used to read..."
-
Tags
Summary
Sticks and stones may break my bones, but words shall never hurt me
— Unknown (first written appearance, 1830)Crime prevails. In every street, in every corner, every twisted apparition of kindness has a perception of to gain and to lose. Quid pro quo taken to its natural eventual conclusion.
Mercy is not an option in this world. And yet, there lies a soul DETERMINED to do something right, and another begging for a release that will never come.
Unlikely souls meet in the beyond, and take a journey to discover what went wrong, and how did it all go bad so quickly?
Series
- Part 1 of sticks, stones & bones
-
Tags
Summary
Frisk Dreemurr, beautiful spoiled brat, had the absolute talent to make people like her, please her, simply said the right words, looked as gorgeous as ever and in her small palm she had them.
She was his responsibility, he had to keep her in check, watch her every move, keep her safe, take care of her, be there for her if somebody hurt her, even if that somebody was him.
-
When pure Lust breaks a Mobster's mind (Mob/Lust) by Chris_ghosty77
Fandoms: Undertale (Video Game)
29 Oct 2025
Tags
Summary
Mob has been in worse situations before, he's sure they'll get out of this mess. Lust, the prostitute keeping him company while waiting for the police to release them, isn't so sure. The officers have a devious plan to make sure neither prisoner will ever be the same when (if) they get released. Now with the possibility of choosing the poor skeletons' fate!!!
Warnings in the tags.Series
- Part 15 of Undertail hypnosis series
-
Tags
Summary
Mafiafell take I had made.
Constant war meant the development of new methods of destruction. Hopes of catching everyone else off guard with a weapon they couldn’t combat or find a way around just long enough to stay on top until the newest shiniest thing made its way to the market. Mechanical enhancements, biological modification, higher powered weapons. Its a constant struggle for king of the hill, a never ending toppling and growing market with worse and worse.
-
Tags
Summary
Disoriented and emotionally frayed from decades spent in the void, W.D Gaster suddenly finds himself at the mercy of a cold and arrogant alternate self. His doppelganger promises to return him to the void once his research is complete but before he can make good on his threat, Gaster is introduced to this world’s variant of his son and he is forced to make a quick, spur of the moment decision.
This sole act sends unforeseen ripples throughout the Multiverse and hurdles Gaster on a perilous journey across it to find his way home.
or
Dadster plays hopscotch across the multiverse, unintentionally and intentionally acquires children, tentatively reciprocates Grillby's feelings, engages in actual literal custody battles with copies of himself, somehow steals a Bad Sans™, narrowly avoids death at the hands of Error and somehow flies under Ink’s radar for a shocking amount of time.
-
Bare Bones (Undertale Mafiatale/Mafiafell/Mobtale Sans and Reader Enemies to Lovers Romance) by aleppost
Fandoms: Undertale (Video Game)
06 Oct 2025
Tags
Summary
After your mother (the last person that cared about you) passes away and you lose your job, you decide that you are going to move out of Ebott City to start a new life. On your last day in Ebbott City you make a wish into a fountain, and end up falling in. When you get out of the fountain however you find yourself face to face with a pair of skeleton brothers, and for some reason its now the 1930's???? It turns out that the Skeleton brothers are the head of the Mafia that runs your side of the city, and you now live in their district. Papyrus seems to be nice, Sans however is skeptical of you and your intentions and makes it known pretty quickly. Reader has to navigate living in a different time and figure out what their life will look like moving forward, and she wants these strange skeletons to be a part of it.
This is a slow-burn romance where Sans doesn't want to like you, but cannot seem to stay away. Enjoy!
-
Tags
Summary
What happens when everything changes? Everything is the same but it isn't.
An entity from the stars descends to earth and disguised themselves as human. They witness history in this new era of monsters and humans, while also dealing with the demons that dare dirty the earth with their presence.
What happens when you step into the battleground from one universe, only to win and come out into another parallel world, except you’re the protagonist?
You weren’t one for the spotlight. You loved your sister, even if she wasn’t one by blood. You only wished for her well-being and happiness. Except here… she’s gone. And now you have to take her place and stand under the limelight as you walked your path in her place - the protagonist.
————
I DON’T CONDONE MY WORKS TO BE TRANSLATED, REPOSTED AND/OR FED TO AI.
9/1/25 — thank you for 600+ hits!
Series
- Part 2 of Still As Stone AU
-
ArcaneFell: Under His Protection by Witch_of_Ragnarok
Fandoms: Undertale (Video Game), MafiaFell AU (Original Undertale AU), ArcaneFell AU (Original Undertale AU)
30 Aug 2025
Tags
Summary
Six years before slavery is banned, Sheriff Marrow finds a dying human girl in the snow — and chooses to save her, even though he shouldn’t.
He names her Garnet.
She becomes the one thing he cannot let go of.In a world ruled by ownership and fear, their bond is both salvation and disaster. Garnet’s lost magic returns. Don Gaster takes interest. And the lines between law, loyalty, and love begin to blur.
A forbidden romance set long before ArcaneFell: Let Me Stay — where protection is power, and love is the one crime no one survives untouched.
Series
- Part 3 of ArcaneFell
-
Tags
Summary
Mobtale AU. Since the sudden deaths of her husband and son, Toriel has never been the same. What once was a kindhearted Queen turned into a leader that rules with an iron fist. Distant and changed, Sans worries for his friend. What started as a simple joke lands little orphan Frisk with a troubled past at her doorstep. Being able to love again starts to become a possibility for Toriel.
However, there is always something in the shadows and it will take pure grit and determination to stop it. -
Tags
Summary
When invertos, people turned into monsters by their own innate magic, come about, they're herded into a facility to await True Monsters to host them, so the they can better learn to understand their new magic. That was seven years ago, and now it's just me in the facility. I've got some visitors now, and I think they're monsters hosting me out. Will I finally get out of here or is it just a false hope?
Fluff galore. Hurt Reader. Overprotective skele bois. It’s gonna be a bumpy ride. Luckily though, MC has been wrapped in blankets and pillows and bubble wrap!!
Read the comments if you’re up to it! I try my best to respond to every single one and you can find hints to future chapters and plot lines in them!!
-
Doin' It Right (ON-HOLD. Will resume on December 2025!) by vidrioborroso
Fandoms: Undertale (Video Game)
31 Jul 2025
Tags
Summary
Monsters are free, and Frisk is safe and sound at home.
It feels like fairy tales are real, though a rough break-up after eight years of marriage quickly sobers that thinking.
With the break-up follows a proposal straight out of a steamy novel: share a room with a man you've just met, while you get back on your feet and work on the process of finding a new place to move into.
Turns out, the guy who smells like grease and beer from how often he visits Grillby's is a lot less romantic than you would think.
And it's precisely living together what gets you to know all the icky things about him.
Until you end up falling for him with each nice little thing he does, and suddenly...
It feels like all those icky things start to matter less and less.
More so, when things take a sharp turn and you're in the middle of a gang fight, helping him however you can despite not knowing what you're signing up for.
Overlooking details like bloody clothing, chipped teeth, and reports of missing people on the telly make seeing him drinking straight from the milk carton a much more tolerable offense.
-
Tags
Summary
You spend your days reading and making deliveries for your carrier job, life is pretty normal. Weeeell, that's until you meet some well dressed skeleton brothers under..... uncomfortable circumstances. But that's alright! You'll work hard to make up for past mistakes. Relationships may grow although, someone might get a little "handsy" in the future. Welcome to my very first fan fic, but certainly not the last ;3
-
Tags
Summary
Once known as one of the best scientists of the Royal Guard, Sans lives on logic and logic only.
He's rejected the idea of soulmates being real, too stubborn to picture it as something remotely plausible.
So, when he starts to gain glimpses of a thin red string tied to his only other human friend besides Frisk, Sans ignores that for an entire year.
Unable to accept his new reality, he drinks himself to near intoxication, and then his drunken self wanders into Grillby's, searching for the woman responsible for making him feel this way.
-
Three High Ranking Members of the Mafia and a Serial Killer Walk Into a Bar... by Larry_your_waiter
Fandoms: Undertale (Video Game)
11 Jul 2025
Tags
Summary
Sans has his own share of secrets, as the family will soon discover.
a series of non-chronological scenes in this AU of an AU because I can.
-
Tags
Summary
After his fifth overtime shift in a row, Sans is as tired as he is tense.
Good thing he has a secretary to help him with that.
Series
- Part 2 of Smutty Sans/Reader One Shots
-
ArcaneFell: Dreamland’s Hidden Horrors by Witch_of_Ragnarok
Fandoms: Undertale (Video Game), MafiaFell AU (Original Undertale AU), ArcaneFell AU (Original Undertale AU)
24 May 2025
Tags
Summary
ArcaneFell — a dark-fantasy Mafia AU of Undertale.
Meet the Rookie — a young feline grunt trying to survive his first day in the mafia under the looming shadow of Don Luceris Gaster.
Assigned to Stonehand, a battle-hardened beetle monster with deep roots in the black market, the Rookie is thrown into Dreamland City’s criminal underworld.Their mission: reach the Golden Vault — the country’s most notorious underground auction house — and secure a high-value item at any cost.
But what begins as a simple assignment spirals into something far darker.
For the Rookie, this isn’t just about bidding wars or underworld politics.
It’s a brutal lesson in what it truly means to serve the Family — where loyalty is a weapon, betrayal has a price, and one wrong move can get you buried under the marble.Series
- Part 1 of ArcaneFell
- Language:
- English
- Words:
- 3,042
- Chapters:
- 1/1
- Kudos:
- 1
- Hits:
- 20
-
"Sooner Or Later You're Gonna Be Mine" As Seen On TV - Now With Added Ending! by And_So_The_World_Went_Quiet for All you LOVELY people!
Fandoms: Undertale (Video Game)
07 Apr 2025
Tags
Summary
You heard right, folks! I've taken it upon myself to rewrite the INFAMOUS "Sooner Or Later You're Gonna Be Mine" Fanfic by Staringback!*
Come one, come all, to see An Ending of this miraculous Fan-Fiction! come for the ending, stay for the rewrite, as I intend to do my best to make it not only easy to recap, but with added content and editing that’s enjoyable for the whole family!
... or, at least most ages over 18!I WILL complete this fic, I'm still working on it, I just don't have a schedule anymore because I'm adjusting to a second job. Do not lose hope.
*please read the author's note in the first chapter and all applicable tags, thank you
-
Tags
Summary
Set in the 1920's, this fic was heavily inspired by the Mob/Gangster AU's for Undertale.
Frisk and Chara live a struggling and complicated life on the city streets, having ran away from the orphanage just to survive. With Frisk being the optimistic younger friend, Chara is the brains of their dynamic duo as well as pessimistic, and willing to do whatever it takes to help them survive. The two manage to get by, but it’s on a fateful day that a promise is made, and suddenly the two are separated… by a mobster group known as the Underground, resulting in not just a fight to save their friendship, but a fight to save each other’s lives.
-
Tags
Summary
no matter what form, no matter what world, and no matter how many times, you'll fall back into familiarity with him as he will you.
(or one shots i've written from ambitious ideas for multi-chaptered fics i've had, most if not all tooth-rotting fluff with a slice-of-life touch to it. almost. mayhaps. perhaps a little bit of hurt/comfort sprinkled in.)