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  • Hey, Doll | Gaster!Sans x Reader
    259K 13.1K 47

    Alone in a condemned world where monsters and humans fight for power constantly, Y/N survives off of the wood's riches and the small scraps of shelter she can find in ghost towns. Allies and friends have come and gone during the war, either killed or have parted ways. It's not all that bad. She could be dead, after al...

    Completed   Mature
  • Daybreak [ Error!Sans x Reader ]
    90.9K 3.7K 27

    Gone. In a single moment, in the blink of an eye, everything you have ever known or cared for is eradicated. Hopes and dreams, traditions and stories that date back centuries have been erased without thought or care. Nothing matters and no one will ever live again to pass on the memories and stories of what was lost. ...

    Completed  
  • When Two Fates Intertwine (Sans x Reader)
    89.5K 2.4K 12

    [THIS IS A SEQUEL TO MY OTHER FANFIC "WHEN TWO SOULS MEET!" If you haven't read it, I would highly suggest it--the story won't make much sense otherwise.] Sans has finally found someone he can trust--Frisk's sister, the eighth fallen human. After months of step-siding and awkward interactions, the two are finally a co...

    Mature
  • Unexpected Love | Sans x Reader
    319K 9.7K 35

    You climbed the famous Mt. Ebott to prove to a group of your friends that humans don't disappear when they go up the mountain. While walking around the peak, you trip over a root in the ground and fall forward, expecting to hit the ground. Instead, you were met with open air. As you fell down the large hole, you let o...

    Completed  
  • Ran into You (Ink!Sans X Reader)
    90.4K 3K 20

    -Starts with UnderSwap- You were at home with Chara, enjoying a regular day. Since you'd gotten to the Underground, you'd become close friends with many monsters, even if your soul was what was needed to free them. You were about to eat dinner with your friends when disaster whisks you away from your home and into a...

    Completed  
  • Lights Like Stars (Sans x Reader)
    142K 5.3K 37

    It's been over a year since the Underground opened up and the monsters living under the earth swarmed to the surface in their thousands. The human and monster governments are taking their sweet time coming to any kind of agreement regarding monster rights and citizenship, but for the most part, in the less politicall...

  • Stuck in Between (Reaper!Sans X Reader)
    122K 4.8K 20

    When your heart stops, you're supposed to stop there. But when your heart stops in the Underground, your soul resets. But what if the reset doesn't work. You're stuck in a stalemate between life and death after your attempted reset glitches. Memories fuzzy and distant, lonely and cold, what does one do to survive thei...

    Completed  
  • Fall of the Empire [ Sans x Reader ]
    56.6K 2.6K 23

    You weren't quite sure what you were. As time progressed, you had been called many things. Hope, future, a new beginning. You weren't quite sure why they called you those things, for each passing day you say locked in a cell, waiting for the freedom that would never come. You weren't alone. You grew fond of two other...

    Completed  
  • Chainsmoker [ Gaster!Sans x Reader ]
    30.4K 1.7K 15

    Routine. The entirety of every living thing is dominated by it, human or monster. Everything HAS to be the same. It was in this that you were the exception. For you everything was new, every time line a detailed altered in order to satisfy your sadistic desire for a new ending, whether it be only a few details of dial...

    Completed  
  • For Your Sake (Gaster!Sans X Reader)
    60.4K 3K 20

    THIS IS A SEQUEL BOOK!!! IF YOU HAVE NOT READ THE FIRST BOOK YET THEN GO FIND IT ON MY PROFILE!!! Anyway, now for the summary: After death, you hadn't expected much to happen. You fell immediately into a place like the void. You just wanted to reconcile for what you'd caused, but your heart had a wish of its own. You...

    Completed  
  • The War Amongst Us (W.D. Gaster X Reader)
    64.3K 2.9K 24

    (Y\N) is a young female spy and soldier fighting in the War of Humans and Monsters. She is fighting on the humans' side of the war until a turn of events when she becomes apprehended by the enemy. What will happen when a young monster scientist tries to change her views? Thanks to Itachei on Deviantart for letting me...

  • Puns ( Sans x reader )
    495K 16.3K 12

    Warning! There is a chance that there will be spoilers for the pacifist run of undertale. I recommend finishing that before reading this. There won't be any spoilers for the no mercy run, so don't worry about that! Also, don't worry about anything NSFW/lemon if that's not what you're into-there won't be any of that he...

    Completed  
  • Gunpoint (Sans X Reader Fanfic)
    9.2K 535 11

    They all knew there would be trouble when the surface saw monsters for the first time in centuries, but no one knew it would be like this. War, bloodshed, tears and death soaked the world and only a handful of so called politicians were to thank. You were in college when you applied to be the ambassador of humans to s...

  • Chat Logs | Sans x Reader
    547K 27.2K 86

    Sans and Alex happen to meet trough a chatbox. What will be the outcome when two completely different people become more than friends? This is an actual slow burn holy shit

    Completed   Mature
  • Blown Through The Rift (Gaster!Sans X Reader)
    244K 9.5K 35

    You were working with Alphys in the lab in Undertale when chaos strikes! In a freak accident, concentrated determination is mixed with an unnamed concoction and blow you through a dimensional rift. When you reawake, you find yourself in what seems to be the beginning of Undertale once again. Upset but not overly surpr...

    Completed  
  • Before the Storm ( Sans x Reader )
    12.4K 643 21

    There's something wrong with the timeline. You've lived in an underground crypt with cracked green walls for as long as you can remember. And that's entirely the problem, you can only remember so much. Even as tortures and experiments continue without end, you're plagued with nightmares and glimpses into a different l...

    Completed  
  • The Soul Within Us (Sans X Reader)
    72.7K 2.2K 28

    (Sans x Reader Slow burn. Cover drawn by me :D) They made it to the surface. Again. But how long will it last? Frisk made a promise.... But how long will they keep it? Sans is unsure, and anxious; depressed. A smile with sad eyes as usual. Then he meets y o u. Heh.. Did you really think you would change anything...

  • Bone of Contention (Underswap Papyrus X Reader)
    368K 14.5K 62

    Humanity is divided over one thing---the Monsters' reappearance. Some believe that they should stay aboveground, and others think that they should be sent back to where they came from. Then, there are those like you who don't quite know what to think yet. What will happen once you become acquainted with two skeleton b...

  • At the Surface (Sans X Reader)
    502K 20.5K 62

    The monsters have finally made it to the surface and have been legalized to roam the surface as they please. The first couple of months have been spent as a paradise where humans and monsters have lived in peace and happiness. But as we all know, humans tend to be afraid of what they don't understand and the appearanc...

    Completed  
  • (Sans x Reader) When Two Souls Meet
    935K 27K 28

    Sans has lived through countless timelines. He's seen the kid make friends with everyone, only to give up in the final moments. He's seen the kid killed, over and over and over again. Sometimes, he'd even done the killing himself. And no one ever remembers. Not even the kid herself. It's an exhausting cycle, one that...

    Completed  
  • Ursa Major (Sans X Reader)
    150K 5.7K 24

    It had been a couple months since your little sister went missing. Guess how surprised you were to see her on the news with the headline "Young Girl Helps Monsters Escape". When you meet the friends she made in the underground you can help but to love all of them, especially a skeleton with a love for puns and stars...