#1
Big Sister Undyneby Moonstone_Ccino
Underfell is a dark world with the major rule of kill or be killed. Even though children are suppose to be secluded from this rule, that doesn't stop monsters from hurti...
#2
Undertale/Au's x reader 4by Artsy is bored.
Here's the fourth book! thank you all for all the love and nice comments on the first, second, and third book!
NO LEMONS! FLUFF AND YANDERE ONLY!
Mostly Au sans and pa...
Completed
#3
Living In Hell. {Depressed Underfe...by Chey Kennedy
Underfell, a place where hell shows no bounds, and its kill, or be killed. Sans, a weak and looked down upon monster, suffers in a town, a place called Snowdin. But noth...
#4
The Return(A Flowerfell Sequel)by Frisk
3 years had passed since Frisk sacrificed herself to free the monsters.
Now humans and monsters live together on the surface, though some monsters preferred staying in...
#5
'Being A Pet All Over Again' Under...by noé
[Disclaimer that this book is very old nd poorly written, please keep that in mind!]
Sequel to 'Shy Pet' so if you haven't read that, I suggest you do!
After Y/n had die...
#6
Christmas Party AU (undertale au's...by OlinArtz
This is inspired by the one and only _Sansational_Sans_
The original concept goes to _Sansational_Sans_ and the Christmas Party AU does not belong to me!
Gender neutral...
#7
HoneyMustard {human ver.}by BluePerry
I've been reading plenty of honeymustard fanfic and I wanted to start my own? no one is going to see this but eh. I'm currently writing the first part at 4am so it'll pr...
#9
Broken Dollsby Komeri Makara
Sans had gotten used to the experiments and tests done by Doctor W.D. Gaster. Then he was introduced to a younger monster. What he would do to keep him happy and safe st...
#10
Truth or Dare Underverse (Lol disc...by Undertale_tRaSh_4U
!!! WARNING THIS BOOK IS DISCONTINUED!! WE ( Aurorawe and tRaSh) HAVE A NEW ASKBOOK! IF YOU'D LIKE TO ASK OR DARE CHARACTERS PLEASE GO TO THAT BOOK CALLED "Ask or D...
Completed
#11
Mosaic [Undertale AUs]by DeadEnDead
To escape a timeline ruined by a cruel queen, Sans uses a machine to find somewhere safer for his younger sibling. Unfortunately, the machine can only take one, leaving...
#12
Something Stressfulby baembo
A repair turns catastrophic when Sans's machine, built to get the skeletons back to their universes, tears through the fabric of reality- more versions appear, but he un...
#14
Pet (Lazyberry)by mehfigure
Blue is gonna get what he wants no matter what...
⚠️ WARNING⚠️
This contains heavy forced lemon, kidnapping, mixed emotions, this shit probably needs to burn in hell alo...
#15
101.- Rudo? (Fell!Sans x Lectora)by ecchisforlife
Quizás rudo no sea la mejor palabra para describir a la persona que te salvo la vida, no?
Créditos a:
- Toby Fox
- Creador/a de Underfell
Avisos:
~Underfell~
~Sans~
~Fel...
Completed
#16
Need some help from other internet...by Russ
Just need some help finding a specific story from awhile ago
#17
★彡 𝐔𝐍𝐃𝐄𝐑𝐓𝐀𝐋𝐄 𝐀𝐔'𝐒 𝐎𝐧...by ★彡 𝔪𝓛ℓƗⓝη 彡★
ᴛʜɪꜱ ɪꜱ ᴀɴ x ʀᴇᴀᴅᴇʀ ʙᴏᴏᴋ, ʜᴇʀᴇ ɪ ᴡɪʟʟ ᴡʀɪᴛᴇ ꜱᴍᴀʟʟ ꜱᴛᴏʀɪᴇꜱ ᴡɪᴛʜ ᴅɪꜰꜰᴇʀᴇɴᴛ ᴜɴᴅᴇʀᴛᴀʟᴇ ᴀᴜ ᴄʜᴀʀᴀᴄᴛᴇʀꜱ, ᴀɴᴅ ɴᴏᴛ ᴏɴʟʏ ꜱᴀɴꜱᴇꜱ.
(ʜᴏɴᴇꜱᴛʟʏ ꜱᴘᴇᴀᴋɪɴɢ, ᴍᴏꜱᴛ ʟɪᴋᴇʟʏ ᴛʜᴇ ᴄʜᴀᴘᴛᴇʀꜱ ᴡɪʟʟ...
#19
Ask Underfell Sansby Pepsiwriter
Ask your questions here and I may answer them, perhaps, most likely....if the boss is ok with it.
# Third place in the 2nd Ohana Awards #
I do not own Underfell. That...
#20
Fell Papyrus X Readerby Sans and Papyrus
You have Fallen into the underground. You made it Past a murderer Goat called Torial. You seen two skeletons One Tall Called Papyrus and one small called Sans. Now you a...