1 - 20 of 397 Bookmarked Items in Alternate Universe - Underlust (Undertale)
Navigation
List of Bookmarks
-
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..."
-
Bookmark Tags:
-
Making A Monster by absurdmagewrites
Fandoms: Undertale (Video Game), Underfell-fandom, Underswap-Fandom, Swapfell-Fandom, Fellswap-Fandom, Fellswap Gold-Fandom, Horrortale-fandom, Crafttale-Fandom, Seaswap-Fandom
16 Nov 2025
Tags
Summary
Sometimes life throws you a curveball. For you, your curveball was going to bed looking like a human, and waking up looking like a monster.
A skeleton monster to be precise.
With the barrier breaking, a large surge of magic descended on the town you live in, and transformed you overnight. Unsure what to do with you, and the others changed, you're ushered into a facility until a monster with similar magic can take you to teach you how to wield the now uncontrollable magic you've been given. After waiting in this place for four years, you'd given up hope that anyone would ever want to take you.
What a surprise for you when you find out that someone does. A lot of someones.
- Language:
- English
- Words:
- 729,287
- Chapters:
- 93/?
- Comments:
- 4,503
- Kudos:
- 4,752
- Bookmarks:
- 1,056
- Hits:
- 277,942
-
Bookmark Collections:
-
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!!
- Language:
- English
- Words:
- 22,262
- Chapters:
- 28/?
- Comments:
- 615
- Kudos:
- 1,027
- Bookmarks:
- 251
- Hits:
- 24,914
-
Bookmark Notes:
chpt 28
-
Tags
Summary
In Underlust, where almost every monster is hypersexual due to being injected with lust in order to increase the monster population, Mettaton is an outsider. As a ghost, he was not injected with the lust substance, and as a result, he is completely different from everyone else in the Underground. He feels out of place as an anxious bookworm who has little interest in sex and is losing hope because his quiz show is unsuccessful. But Mettaton might not be as alone as he thinks. A certain skeleton loves Mettaton's show and wonders if anyone in the Underground shares his rare capacity to prioritize love over sex.
UNDERLUST DISCLAIMER: I think it's important to acknowledge that there are some problematic things about Underlust and that I absolutely do not condone those aspects of the AU. However, Mettaton's story in Underlust is important to me, so any senseless hatred of him or of the AU is not appreciated.
CONTENT WARNINGS: Graphic descriptions of sexual assault and attempted assault, PTSD, depression, self-harm, and suicidality. If you don't feel comfortable reading about those things, I'd highly suggest not reading this story. Please stay safe and take care of yourself!
-
Freeing a caged dove (Underlust Bitty fic) HIATUS by Nightwilf
Fandoms: Undertale (Video Game)
31 Oct 2022
Tags
Summary
You are in a club at a friend's insistence and escape the crowd after a riot happens, not realising you leave with a new friend.
-
Summary
Undertale Multiverse where the Sanses know each other, but with wings. Wings are an extension of a monster’s soul and are typically used as a form of expression or fighting.
Some of the AUs will not have wings, though, since they are technically alternate universes and can be made without them.
Series will consist of (probably) one-shots surrounding the characters, and I’ll probably take suggestions after the first two stories are done. Just because I make a character or relationship one way doesn’t necessarily mean I won’t write something else entirely if I like it, it just won’t be “canon” to the series.
(〜￣▽￣)〜- Words:
- 129,084
- Works:
- 10
- Bookmarks:
- 303
-
Bookmark Tags:
-
Crossing the Pick-Up Lines by Kamari333 for Skullcrysto, Acoustic_Meatus
Fandoms: Undertale (Video Game)
27 Jul 2025
Tags
Summary
An Underfell Sans is finally adjusting to surface life when a slutty alternate reality clone steals his drink.
How did this turn into a date?
- Language:
- English
- Words:
- 5,107
- Chapters:
- 1/1
- Collections:
- 2
- Comments:
- 27
- Kudos:
- 30
- Bookmarks:
- 7
- Hits:
- 169
-
Bookmark Notes:
A Red/Dust (Rust) fic! Had the pleasure of beta'ing this one for Big Bone 2025. The best kind of meet cute you could imagine for these bois.
-
Tags
Summary
Lust, a captivating massage therapist, finds solace in two unlikely relationships with Red, a fiercely protective teacher, and Dance, an exuberant skeleton with a traumatic history. As they celebrate the anniversary of their unconventional love, a dark twist shatters their fragile happiness.
(It has a happy ending.)
-
Tags
Summary
You live in the middle of nowhere and you like that. You have never been much of a people person and when you inherit a mansion on the mountainside far away from the bustling city of Ebott well you practically jump on the opportunity. Only keeping a few helping hands around. You've started your own business making a variety of art-based things such as paintings, pottery, commissioned drawings, knitting, and various other things. You have a perfect life, admittedly a bit lonely from time to time but that is what your cat and horse were for as well as your beloved sister who insisted on dragging you out of the house every other week to do something crazy yet fun.
That is until one of those “fun” activities ends up leading you to sponsor a couple of monsters. *Sigh* Nothing prepares you for the pun-loving skeleton and his cinnamon roll of a brother but hey at least you're getting paid for the trouble right, but wait! Wasn't there only two? Why is there 4...6...8..10.. gahhhh! How many skeletons are there and where do they keep coming from!?
Your life is about to go from 0 to 60 real fast, so buckle up buttercup.
-
Tags
Summary
Sans has put in the bone work.
For fifteen years, he's raised Papyrus.
Not even counting the time loop.
And now some pretentious ancient bones want to have a say?
Oh hell no.
-
Said "ancient bones" are mortified.
How were they supposed to know the short depressed skeleton was barely two decades old?!
- Language:
- English
- Words:
- 209,106
- Chapters:
- 49/?
- Comments:
- 1,816
- Kudos:
- 1,533
- Bookmarks:
- 335
- Hits:
- 56,812
-
Bookmark Collections:
-
Bookmark Notes:
Leer 50
-
Flash Fics for Whittney by Mochimunchies for WhittneytheScorpionSuccubus
Fandoms: Undertale (Video Game)
20 Apr 2025
Tags
Summary
A short collection of flash fics/oneshots written for Whittney!
Includes:
Chapter 1 - Errorberry (Mer AU)
Chapter 2 - Bad Sans Poly + Star Sans Poly
Chapter 3 - Errormare + Errink
Chapter 4 - Horrorlust
Chapter 5 - CrossmareSeries
- Part 4 of Flash Fiction Giftfics
-
Bookmark Collections:
-
Tags
Summary
You find yourself sleeping in your car in winter. Being strong enough to get out of an abusive cheating relationship, you opt to sleep in your car rather than be stuck in a bad relationship. While you are wracking your brain to find a solution to your situation, you run into an old school friend and her pack of skeletal boyfriends. Your own situation not being the best, you want to avoid stepping into the situation, however one skelly just can’t let you freeze in the cold. What comes next is a story of betrayal, healing, and helping those that haven’t yet learned to help themselves.
Mutt didn’t like the human that the rest of his house has as a datemate, what he didn’t count on was ending up falling for the one person that might be able to help everyone in the skeleton household.
- Language:
- English
- Words:
- 568,406
- Chapters:
- 213/?
- Collections:
- 2
- Comments:
- 2,882
- Kudos:
- 2,095
- Bookmarks:
- 401
- Hits:
- 115,069
-
Bookmark Collections:
-
Tags
Summary
You're an artist and singer, you live at home alone.
One commission from an Undertale fan sends your home into chaos when uninvited skeletons invade your home.Will they get back to their world and will you fall in love?
-
Bookmark Collections:
-
Bookmark Notes:
chapter 36
-
Tags
Summary
In a Multiverse where Ink and Error retire together after falling in love. Dream is now the new leader of the Star Sans and protector of the multiverse.
With Error no longer a threat, Dream focuses his effort in pacifying the other big threat to the multiverse, his brother Nightmare. In an attempt to cure his brother of his curse of negativity, Dream uses a rather volatile serum from a rather lewd AU.
How will this series of events play out? And how will the multiverse fair without Ink and Error?
Relationships/Ships:
Nightmare/Killer (Killermare)
Error/Ink (ErrorInk)
Underlust Papyton & Sansby-
Bookmark Collections:
-
Bookmark Notes:
Mmm porn- GUYS WHO SAID THAT??😨
-
-
Undertale Alternate Universe Nicknames: All Main Characters by Creator_Kai
Fandoms: Undertale (Video Game), Deltarune (Video Game)
01 Oct 2025
Tags
Summary
A compiled list of various Nicknames for Undertale Alternate Universe Characters. This is a FULL list created by myself for all the Characters throughout the Undertale Multiverse. It's not complete and likely never will be because of how many AU's exist, but there is quite literally no better list than this one if you are looking for Character Names to use in your UTMV stories.
Includes:
—Sans AU Nicknames
—Papyrus AU Nicknames
—Frisk AU Nicknames
—Chara AU Nicknames
—Toriel AU Nicknames
—Asgore AU Nicknames
—Undyne AU Nicknames
—Alphys AU Nicknames
—And many more-
Bookmark Notes:
very nice very nice
-
Tags
Summary
Wake up buried in snow, alone, and with no memories?
Check.Keep seeing numbers, words, and random text floating around every object and surface as far as the eye can see?
Also check.Why does every person he meets say he needs help?!
He’s perfectly fine, if you ask him.“I wonder what determination tastes like.”
---
Note from the author:
This is my take on Fatal Error — a much more non-canon,[this isn’t even OOC, this is just straight-up a different person with the same name]
amnesiac version of him.
He’s also not fully canon-compliant in terms of power scaling and may even have a different origin and and backstory.It’s my reimagining of him with a completly diffrent story.
-
Bookmark Notes:
36
-
Bookmark Notes:
I enjoyed this quite a lot when reading this for the first time so I hope to see more soon
I REALLY liked this take on fatal error as well, I think it's pretty neat
anyways, kudos to you writer :D -
Bookmark Notes:
35/
-
Bookmark Tags:
-
-
Tags
Summary
You were a normal human. You went to college, you had a life, friends, family, etc. Apparently, the void didn’t care much for happy endings, and you find yourself strapped to a table in an underground lab.
It’s fine, you have plot armor.
———————————
Or, you get sucked into the void and your soul is placed in the body of eight-year-old Sans.
Arc 1: Heritage (1-7)
Arc 2: Hell (8-10)
Arc 3: Home (11-45)
Arc 4: Heart (46-59)
Arc 5: Hostage (60-?)Series
- Part 1 of How To Be A Human Being
- Part 1 of Hounds Of Love
- Part 1 of I/Me/Myself
- Language:
- English
- Words:
- 226,769
- Chapters:
- 75/?
- Collections:
- 6
- Comments:
- 2,084
- Kudos:
- 1,685
- Bookmarks:
- 333
- Hits:
- 56,086
-
Bookmark Notes:
Chapter 57
-
Bookmark Tags:
Bookmark Notes:
75
-
Bookmark Collections:
Bookmark Notes:
9
-
CrushingOn Stupid One-Shots by CrushingOnSans (CrushingOnRazz)
Fandoms: Undertale (Video Game)
20 Oct 2022
Tags
Summary
Alright so this is just a ton of bullshit, welcome. One-shots, lots of one-shots. Also lots of procrastination. It's great, you'll love it, I promise. If you look closely you can see exactly when my OTP changes (I'll give you a hint it happened twice)
Feat. Dumb Titles (hell yeah)
Series
- Part 1 of COSOS Stuff
- Language:
- English
- Words:
- 311,341
- Chapters:
- 142/142
- Comments:
- 3,991
- Kudos:
- 1,197
- Bookmarks:
- 81
- Hits:
- 47,694
-
The borderline between the magic larynx, reality, and chocolate molten lava cake by KennieMorguen
Fandoms: Undertale (Video Game)
17 Mar 2025
Tags
Summary
Silly summary: Lust and Red play 7 minutes in heaven at a party. Except...it isn't 7 minutes, there was no pulling names out of a hat at random, and Lust is disassociating. Fun times ensue!
Not so silly summary: Lust is an outcast, ostracized by most monsters outside of his AU with very few exceptions, and even those exceptions were those that Lust never really considered his friends. One day he gets an invitation to a party, curtesy of Blue, so of course Lust makes his appearance. At the party, Lust finds none other than Red, a monster that though he finds him attractive, the Fell monster was a constant bully and instigator in his life since venturing out into the multiverse. Why Red does this to him? He'll have to learn the hard way.
-
Bookmark Tags:
Bookmark Notes:
The borderline between the magic larynx, reality, and chocolate molten lava cake by KennieMorguen
Summary:
Lust is an outcast, ostracized by most monsters outside of his AU with very few exceptions, and even those exceptions were those that Lust never really considered his friends. One day he gets an invitation to a party, curtesy of Blue, so of course Lust makes his appearance.At the party, Lust finds none other than Red, a monster that though he finds him attractive, the Fell monster was a constant bully and instigator in his life since venturing out into the multiverse. Why Red does this to him? He'll have to learn the hard way.
-
Bookmark Notes:
lust needs friends- any friends! also ice.
red is an asshole, but he gets around to being the friend in the end.
universal cultural differences abound.
-
Tags
Summary
Life was never very kind to you, but you never really knew any other way. You just tried to stay as quiet as possible and out of the way. You thought you were being good, you thought your parents loved you.
But you soon find out they don't, and their final betrayal changes your life completely.-
Bookmark Collections: