Top 14 Long Undertale Fanfics
Ranked by AO3 kudos. Mid-length Undertale fics — 50,000–100,000 words.
Rules to Survive the Zombie Apocalypse
by BattleMaiden13
You have no idea when the world went to shit, but your pretty sure it was either when the dead came back to life and chowing down on anything with a pulse OR it was when you flunked out of college. Either way the world sucks now. You aren't entirely sure how you've survived this long either but your
What If?
by GCN_Fandoms
What if the player never existed? What if instead of Kris, Noelle fell into that dark fountain with Susie? What if Kris has no association with the Knight and knows nothing of the dark worlds? What if the soul that was desperately needed to seal fountains was Kris's and Kris's alone, yet the human i
heal me
by charamelwrites
You were kidnapped by the Bad Sanses gang because you apparently "stole" Horror's axe. All hell breaks loose. arc 1 (1-15): encounter arc 2 (16-?): after
A Futa's Undertail
by only0neMan
A retelling of undertale, except Frisk is older, everyone has a giant cock, tits, and booty, and I get to write it. Lemme know what you think! I wrote this in 3 hours at 1 in the morning. Also, Frisk uses they/them in this because if I'm gonna shapeshift em anyway, might as well make them an enby
It's A Hustle
by Saiyurimai
The life of a prostitute is a lonely one, something Frisk has learned all too well. It also is a dangerous profession. Full of risks and dangerous clients, one of which has just become her regular. But he's not like the others. This strange monster, what could he possibly want with a broken whore li
The Most Dangerous Game
by The_Writing_Mobster
Frisk Starling should've been used to cases like these. After all, it was her duty to investigate. Give the victims their voice back, catch the sick freak who did it and give the broken families the justice she couldn’t have for herself. That is until a string of murders throughout the county begin
Kitty's Undertale Shorts
by KittyCatPaw11
There are a number of little ideas within my head—or strikes of inspiration from fellow Undertale creators—that I'd love to write about! But they need a home... Welcome to Reader x Everyone in the Multiverse! I don't have a schedule, but I try to post often! I hope you enjoy these stories :3c
Fracture (Continued)
by Sviddal
Summary:Aliza had always known she was meant for more than her grandmother's abuse, than her exclusion from society. It was only with the finding of Frisk's journal, and the climbing of the cursed mountain, that she truly came to know her purpose, though. The story of Axetale, created by thebananafr
Gods & Monsters
by Ichigh0st
It’s fun being dead.Or undead, rather, as your sister likes to correct you. Your dear sister is the kind of person who took her dark arts very seriously. Or, her necromancy, rather. You’ll be the first to admit, you don’t know a lot about her school of magic. She doesn’t know much about yours either
Life On the Surface
by RetroWrites
Frisk has freed the monsters.Now all they need to do is to live on the surface.Campy story with plot and sad stuff on top of regular Undertale shenanigans.
Overlaid Pains
by Blueberry_Muffin_Massacre
Things have been fixed for over a year.The nature of their world is known.Everyone is happy. Everyone here is happy.Someone, somewhere else, is suffering.Toriel begins Sleepwalking. A sequel to Outside the Picture Frame. Several characters general state of being and demeanor will not make sense with
New Beginnings and Old Wounds
by Puppy_Chat
Y/N's life in the village is changed forever when a new monster enters her life... Soon everything starts changing and coming to light... The only problem is.... Everyone knows, but her.... (Summary Updated on May 28, 2026)
FransWeek2021
by EchoBlack
2021Frans主題如下Flirt調情Weather天氣Puns雙關語Trust相信Work day工作日Kiss親吻Valentine's情人節這裡只有一些焦慮跟澎鬆的絨毛，有點遲到，做的不是很好但是讓我們完成這個清單吧！：) 我參與的第一個挑戰！
Maniacal Magical
by Swish42
Our protagonist is once again whisked into a new world against his will, while still mentally recovering from the torment of the Evil Doctor of the last world he was in. He is now stuck in a city where Giant Amalgamates and snarky Giant Flowers attack every week and Magical Mew Mew Cutie Girls make
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About This List
This list of 14long Undertale fanfics spans 1,088,609 total words. Kudos range from 7 on the newest entries to 1,180 on the most established. Most entries are ongoing works, so subscribe on AO3 for update notifications. The most common rating is Explicit (5 of 14 fics).
Recurring tags across this list: Fluff and Angst · Hurt/Comfort · Rape/Non-con Elements · Alternate Universe - Undertale Multiverse | UTMV (Undertale).
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