Undertaleau Stories

1.2K Stories

An Error's Doll by EroseWisp
#1
An Error's Dollby EroseWisp
You didn't have a bucket list or anything, but you wished you could've at least read a few more fanfics or done literally anything fun before dying. Oh well, at least yo...
To become a parasite by KarmaAkabane425
#2
To become a parasiteby Karma Akabane
What if..someone became the same parasite that was fresh? Not as the skeleton, but the parasite, the thing is, when this parasite gets memories of another life and their...
Insomnia- Accidental Love by CaptainPluffer
#3
Insomnia- Accidental Loveby CaptainPluffer
There are two sides in the Multiverse. There are the Star Sanses, known to be the heroes and saviors of the Multiverse. And then there are the Bad Sanses, known to cause...
Reborn as Error by Kiwi_Seal
#4
Reborn as Errorby Kiwi_Seal
Cover image made by me. Someone meets their end too soon and meets someone who gives them another chance to live a more fulfilling life. One that they would enjoy despit...
I'm...swap gaster? by KarmaAkabane425
#5
I'm...swap gaster?by Karma Akabane
Yeah sorry gained an idea on if someone became swap Gaster Also they may be apathetic or just confused on their feelings and MAYBE Autistic, I may be a bit wrong on ap...
Naturetale : reborn as lavender  by KarmaAkabane425
#6
Naturetale : reborn as lavender by Karma Akabane
(As far as I know, no one has made a story about naturetale like this so..and the only reason why I writing one like this is because of fatal error part 5? Or part 4, go...
The 9th human(Male reader story) by DeleteNine
#7
The 9th human(Male reader story)by DeleteNine
Y/n was playing baseball with his friends when the last ball flew away, he went to the mountain trying to find it but discovered the underground instead. (Cover version...
Prisoner...? (Bad Sanses x Human!Reader) by ShadowOfFandoms10
#8
Prisoner...? (Bad Sanses x Human!R...by ShadowOfFandoms
Y/N was a human from a brand new AU...which was practically nothing. They were eventually rescued by the Star Sanses...only to be taken prisoner by the Bad Sanses. What...
𝐔𝐧𝐭𝐫𝐮𝐬𝐭𝐰𝐨𝐫𝐭𝐡𝐲(Horror Sans x Reader) by Sydneybeartwo
#9
𝐔𝐧𝐭𝐫𝐮𝐬𝐭𝐰𝐨𝐫𝐭𝐡𝐲(Horror...by Sydneybeartwo
​🇦​ ​🇳​​🇪​​🇼​ ​🇸​​🇴​​🇺​​🇱​ ​🇮​​🇳​ ​🇹​​🇭​​🇪​ ​🇺​​🇳​​🇩​​🇪​​🇷​​🇬​​🇷​​🇴​​🇺​​🇳​​🇩​...​🇴​​🇳​​🇪​ ​🇴​​🇫​ ​🇲​​🇮​​🇽​​🇪​​🇩​ ​🇹​​🇷​​🇦​​🇮​​🇹​​�...
reincarnated into my old au by addict_076
#10
reincarnated into my old auby Alien Queen
reader is transported into an old au they made when they were younger read as they go through there daily life in a new form and dealing with new but familiar faces p.s...
The Mother Of Dragons「 Sans & Papyrus Au's x Reader 」 by GoneToSleep
#11
The Mother Of Dragons「 Sans & Papy...by Moe
❝ Long Ago, Lived Monsters, Humans, Mages, and Dragons. All living in peace. Until humanity decided that Monsters, and dragons weren't meant to thrive in peace along wit...
Y/N the Creator (Alphatale Fanfic) by DynamicCiocea
#12
Y/N the Creator (Alphatale Fanfic)by DynamicCiocea
An Undertale fan gets reincarnated into the Alphatale Multiverse. Will they use the knowledge gathered from their first life to their advantage? Or will they perish, fig...
Completed
Who Says You're the One in Control? by ColorfulNoodle
#13
Who Says You're the One in Control?by Colorful Noodle
Papyrus is dead. As are over 100 of the monsters in the Underground. Now it was just Chara against Sans in the Last Corridor. Already prepared to die here, Sans fights m...
Error's book of angst and fluff (finished) by Leffee
#14
Error's book of angst and fluff (f...by Leffee
Please for goodness heavens, don't comment if you're really young, I had to delete enough of cringy comments. Also please don't leave any suggestive comments, there's a...
His Lullaby by AqilahDaWinterWolf
#15
His Lullabyby Creator of Sans Creations
𝐁𝐞𝐟𝐨𝐫𝐞 𝐭𝐡𝐞 𝐀𝐩𝐩𝐥𝐞 𝐢𝐧𝐜𝐢𝐝𝐞𝐧𝐭, 𝐃𝐫𝐞𝐚𝐦 𝐦𝐚𝐝𝐞 𝐚 𝐥𝐮𝐥𝐥𝐚𝐛𝐲, 𝐚 𝐬𝐚𝐝 𝐥𝐮𝐥𝐥𝐚𝐛𝐲 𝐭𝐡𝐚𝐭 𝐰𝐢𝐥𝐥 𝐬𝐭𝐮𝐜𝐤 𝐬𝐨𝐦𝐞𝐨𝐧𝐞'𝐬 𝐡𝐞𝐚𝐝...
Completed
Mer!verse Error (continuation) by UtAU4life
#16
Mer!verse Error (continuation)by UtAU4life
After Error gets ambushed by Ink and his followers, he goes to Outertale where he drops into the bottomless void below. Will he finally be able to have peace for once in...
I'm Kris But In Undertale?! by Anime-lover109
#17
I'm Kris But In Undertale?!by Tsubaki
Y/n was born in the real world but he had lacked adventure in his life. The only thing that had given him a sense of adventure was a few games like undertale and Deltaru...
Becoming dream from dreamtale  by KarmaAkabane425
#18
Becoming dream from dreamtale by Karma Akabane
What if someone from our world became dream on the first day they were made and were determined to not lose their brother to corruption like the original dream did in th...
𝙲𝚑𝚊𝚘𝚜ジ𝚁𝚎𝚒𝚗𝚌𝚊𝚛𝚗𝚊𝚝𝚎𝚍 by Killer-Groves33
#19
𝙲𝚑𝚊𝚘𝚜ジ𝚁𝚎𝚒𝚗𝚌𝚊𝚛𝚗𝚊𝚝𝚎𝚍by Killer-Groves33
𝐴 𝑏𝑙𝑖𝑛𝑑𝑖𝑛𝑔 𝑙𝑖𝑔ℎ𝑡 𝑤𝑎𝑠 𝑡ℎ𝑒 𝑙𝑎𝑠𝑡 𝑡ℎ𝑖𝑛𝑔 𝑦𝑜𝑢 𝑠𝑎𝑤 𝑡ℎ𝑎𝑡 𝑛𝑖𝑔ℎ𝑡 𝑎𝑛𝑑 𝑡ℎ𝑒𝑛 𝑑𝑎𝑟𝑘𝑛𝑒𝑠𝑠. 𝑊ℎ𝑎𝑡 ℎ𝑎𝑑 ℎ𝑎𝑝𝑝𝑒𝑛𝑒𝑑? 𝑊ℎ𝑒𝑟𝑒 �...
How to Establish Your Gang and Take Care of the Children in It by Vraxvaxan
#20
How to Establish Your Gang and Tak...by SuperNova_Studios
Nightmare. King of Negativity. Leader of the Nightmare Gang. He has a lot of scary titles, but he had to start somewhere, didn't he? Horror. Cannibal. Idiot with half a...