1 - 20 of 11,721 Works in Undyne (Undertale)
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Just when her story was about to become a forgotten tale, Queen Toriel Dreemur retruns to the Underground. She shall make her way from the Ruins to the Castle, and discover the new order reigning over her kingdom.
What could have pushed her out of her self-imposed exile?
The Monsters would be curious to find out, if something strange and threatening wasn't spreading amongst them.
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After Basil’s death, Sunny runs towards his home in an attempt to end it all, but Aubrey follows him and she prevents him from dying. Sunny tells her the truth and now they have to face it together.
After moving, they find themselves camping until something happens and now the two will travel together in order to escape the Underground filled with creatures that were only believable to see in fantasy books.Notes:
the Undertale tags are there because I want to make an Omori x Undertale fanfic, but there won't be anything related to Undertale during the first two chapters except for some references to Mt. Ebott and its legend, but around Chapter 3 or 4 onward, the Journey through the underground will begin!
So stay PATIENT!Series
- Part 1 of OMORITALE: Fallen Down (Fan-Series)
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The real world can be a cruel place.
There is no Dark World. No Lightners. No Darkners. No prophecy to set forth a chain of events to whisk away tears and make everything right. No chain of coincidence to magically and miraculously mend broken bonds and build friendships anew.
In the Real World, there is only Kris—lifelong loser and social outcast. Amidst a broken home, an unrequited childhood crush, and the myriad other struggles of adolescence, they want nothing more than to live a Regular life—to be normal—to blend in.
Yet, try as they might, the universe has other things in mind…
Updated weekly.
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UNDERTALE: Surface Tension by Seraph_UTST
Fandoms: Deltarune (Video Game), Undertale (Video Game)
29 Sep 2025
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A long time have passed since Frisk led monsters to freedom. Now sixteen, Frisk finds themselves presenting that very story to a class full of humans and monsters
You'll meet Frisk, now sixteen, free from your control, and still carrying the weight of their choices, doing their best to bridge two worlds with kindness and honesty.
Seraph, your new vessel, a quiet, artistic boy of unknown origin who lives with Gerson and looks up to Undyne like a big sister. His drawings are oddly prophetic… and sometimes, he can feel what others feel.
Lapin, a rabbit monster new to the surface and overwhelmed by the change... maybe even a little lonely.
MK, once known as Monster Kid, now a confident chatterbox still idolizing Undyne (and maybe trying to figure themself out).
Vesper, a bat monster with a protective streak and a soft heart they try VERY hard to hide.
Aiden, Seraph’s loud, loyal best friend, a jokester who’s like a brother to him, always ready to stir up trouble or crack a smile when things get heavy.This is a story about what happens after the story ends. About choices, big and small, that shape who we become.
And sometimes… it gets weird.
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C:\New Folder\New Folder\New Folder\New Folder\New Folder\New Folder (1)\Private\Stories by WheatTooth
Fandoms: Undertale (Video Game)
29 Sep 2025
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Mettaton tells us that Alphys wrote of herself with Undyne, so here's a glimpse at that. While we're at it, also her self-ship fiction with other people she knows (and a couple from her imagination).
Wrote this silliness in 2015-2016 and am just now putting it on AO3.
- Language:
- English
- Words:
- 829
- Chapters:
- 1/1
- Hits:
- 4
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Diving for Justice, Freedom and Managed Democracy by Dangeresque_On_Ice
Fandoms: Undertale (Video Game), Undertale Yellow (Video Game), Helldivers (Video Games)
29 Sep 2025
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The Monsters were dead.
They must have been, the Federation of Super Earth had said so; annihilated during the Great Galactic War along with all the other threats to Managed Democracy. So Clover was understandably confused when he set out to find the five missing Cadets only to discover a whole society of Monsters sealed underground.
What’s more, these Monsters were nothing like the tyrannical, Freedom-hating killers history had portrayed them as.
Things just weren't adding up. But why? It’s not like Super Earth would have lied, right?
Now with a TV Tropes page: https://tvtropes.org/pmwiki/pmwiki.php/Fanfic/DivingForJusticeFreedomAndManagedDemocracy
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lets make it quick
There is a mage, Powerful mage, 7 great mages that sealed monster in the mountain Ebott, The great mage cannot die because their ability and magic in their body, no sickness, curse can kill them, unless you kill them physicaly like stabbing, burn, Etc. the great mages name them self The lightners mage, (beacuse why not), They help on the war, make their kind (human Obv) won the war, but then the disaster happened to themand Our reader (YOU) are the only one that survive, you decide to hide away, but after a long time, you deiced to make orphanage, so you can take care of those precious child of the useless, worthless and trash parents, what a kind of you, You have been running an orphanage for hundreds of years, and of course every 60-80 years you have to change your appearance and make yourself look older gradually over hundreds of years, because a mage of your level cannot do that naturally, you can't even die. To keep your orphanage running, you are doing it this way... better than being burned and destroyed because you are discovered as a mage... right?
But guees what... The baried you guys Made, it decide "hey let's broke and give this mage a bit of life" good luck -
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It's been three years since you fell into the underground and found a family among the monsters of the Ruins. You love your life here with Mom, your ghost buddy Blooky, your prickly friend Flowey, and the host of Ruins monsters who have accepted you as their own, but things can't stay this way forever. Your friends deserve to see the sun, and there's a prophecy to be fulfilled and a barrier to be broken. Your determination pulls you onward.
The only trouble is that you'll have to make it through an underground full of monsters clamoring after the red SOUL in your chest, and each day as circumstances become more dire they lose a little more hope. This is a more desperate underground than the one you landed in. The odds don't look good for one pacifist child with a stick.
Of course, you aren't completely outmatched. You've spent the last three years training for this moment, and you don't intend to let anyone hit you.
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Between Flesh and Bones|an Oc x Canon fic by EmilytheUTfan
Fandoms: Undertale (Video Game)
29 Sep 2025
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Long ago, two races ruled over Earth: Humans and Monsters. One day war broke out between the two races, but you already knew that story, didn't you ...?
2 years have passed since Monsters were freed from the UNDERGROUND and both races have been living in peace once again ... well not completely, some humans believe that thing's would be better off if monsters weren't freed from the surface. They want to stop at nothing to make sure Humans and Monsters never live in peace.
Series
- Part 2 of LazyAngel fics(Sans x My UT OC Emily)
- Language:
- English
- Words:
- 1,051
- Chapters:
- 1/?
- Hits:
- 8
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Save a Horse, Ride a Cowboy by average_alternative
Fandoms: Undertale Yellow (Video Game), Undertale (Video Game)
29 Sep 2025
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Living in the Wild East with Starlo was great. For the first time in a long time, you found yourself truly happy. It seemed like coming to the Underground was the best decision of your life.
That happiness is threatened when the Asgore finds out that a human has been living in his kingdom for months without being caught.
OR:
I turn my fic that originally started out as smut oneshots into a fleshed-out story with angst, fluff, and yes... still more smut.
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Random NSFW art pieces by MettatonsExHusband
Fandoms: Deltarune (Video Game), Undertale (Video Game)
29 Sep 2025
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I draw more than i write so I thought I should share my contributions to UTDR porn. Will update when I make new stuff teehee
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Don't bear the weight of the world alone by SkyWatcher3
Fandoms: Undertale (Video Game), Undertale Yellow (Video Game)
29 Sep 2025
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After her fight with Clover in New Home, Ceroba, in the middle of rethinking her entire life, chooses to save one child's life, and the consequences of her decision changes the fate of the entire Underground forever.
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The Dual Lights in the Underground by therealone12131
Fandoms: Undertale (Video Game), Undertale: Yellow, Undertale: Red and Yellow
29 Sep 2025
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It's been several years since the last human fell into the underground, and today, in the year 20XX, the eighth human falls in, just like the rest. Two unfamiliar, ghostly friends will await this human, but...
The human isn't Frisk.
A whole different adventure awaits this new human.
If you're new to reading this, it gets so much better after the first two chapters, trust!!!Inspired by the Undertale Yellow fan game by Master Sword and the Undertale Red and Yellow mod by Shinix.
Absolutely love their work, I hope my writing can match even a 10th of theirs. -
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When Sans finds himself unwillingly involved with the work of his father; the next human soul comes into play… how is he going to get out of this with him and his brother safe?
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The King of Spades really hates the Lightners. They completely abandoned all the other Darkners, they locked him away, and they turned his son against him. He hates them so much, he swears he'll kill them
Hate quickly fades away when confronted with relics of his past, and he has to ask himself, is killing all the Lightners truly what he wants?
In other words, Spade King is having a mental crisis, Kris is suffering, Ralsei is keeping secrets for their protection, Noelle is becoming stronger, Lancer is trying to connect with his dad, Queen is trying to make up for what she did to Spade King, the Soul and Spamton are being pieces of shit, Jevil is somehow becoming sane, and Asgore wants to bang Spade King
Series
- Part 5 of The Mamamango verse
- Part 4 of Mamamangoverse main fics
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Twin Runes by Thealmoghtbeyonder2099
Fandoms: Undertale (Video Game), Deltarune (Video Game)
28 Sep 2025
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Twin Runes es un AU cómico en su mayoritariamente alegre centrado en los universos Deltarune y Undertale. Una fuerza desconocida ha provocado que aparezca un punto de conexión entre los dos universos, lo que hace que Frisk y la molestia fantasmal Chara tropiecen en la vida de Kris en uno de sus muchos reinicios (para gran disgusto de Kris). Se produce un caos que rompe el juego.
La traducciones del "los pájaros y abejas" hasta el "No sirve pa' nada" no son mías. Del resto de traducciones si son de mi autoría
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Nathaniel Walker was an ordinary man who worked as a construction worker to support his elderly parents, but unfortunately met a sudden end during an accident at work. Upon awakening in what he assumed to be limbo, his regrets and attachment to his life keep him from passing on yet unable to go back since no one could undo death. In the end, the void takes his soul and he fades into nothing.
...Only for him to wake up in an underground lab, confused and afraid, while questioning why he's a skeleton... and a child at that.
Nathan has never heard of Undertale, so he's experiencing this world for the first time, unaware that his mere presence has a drastic change on the story you might be familiar with. Regardless, his goal eventually aligns with all of monsterkind, which is to reach the surface so that he may try and find his family again. However he may just find a new family while he's down there.
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Their King is dead. The six Souls are Gone. Their future lays in ruin.
Frisk has slipped through the barrier and left the monsters with shattered hopes and a toppled monarchy. With no witnesses, it was pure, selfish regicide. They were loved by all, and thus, their betrayal cut all the deeper. For the third and final time, humans had stolen everything from them.
Anger has a way of changing people. It remains in the Soul even as memories fade.
Frisk may be gone, but the RESETS continue, multiplying the resentment within them and morphing the residents of the Underground into tightly wound reflections of their former selves. No longer in a position to do nothing, Sans is Determined to find a way past the barrier for the sake of his brother, and for the sake of justice.
He’ll give anything to achieve that goal. His Soul included.
He’d found an alternate method that should work, buried deep inside a gilded dusty tome in the royal library. Instead of using LoVe to pass through the barrier, Sans was going to use love. He was going to have to gain a consenting human, and convince her to bind her Soul to his. Permanently.
Series
- Part 4 of The Butterfly Effect 💚💛🧡💜💙🩵❤️
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You and Frisk decide to take a day off to have a picnic in Mt. Ebott, something to take your mind off work while waiting for winter.
So why, why are you now on the police office?
Why are you putting missing posters all around the city?
Why did you take them there? Where are they? Why did your worst nightmare become something real?Where are they?
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I don't have a summary i just pulled this out of my ass but if you like a slow burn with a Lot of Words and Feelings™ and Sans pleaseee give it a try.- Language:
- English
- Words:
- 1,710
- Chapters:
- 1/?
- Kudos:
- 1
- Hits:
- 32
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A little bird flies the coop, clipped wings longing to soar, if only until she hits the ground.
Can she pick up the pieces her shattered heart and relearn how to live?Just, pure self-indulgence, really. Expect lots of fluff and shenanaganery.
My own spin on post-pacifist timeline. The monsters are free, but confined to one city, and kept secret from the world. A social experiment is run to see how humans hold up under long term magic exposure and if coexistence is really possible.
Our character, Robin, accidentally gets involved, and discovers a lot more than just magic as her life becomes increasingly intertwined with the lives of monsters of Mountainside.