Twenty-one iterations of W.D. Gaster gambled on plucking a human from beyond their reality to stop a vicious cycle of genocide, and changed the multiverse forever. In a scrambled timeline, away from the grand tragedy of The Angel & The Anarchist, a young woman awakens on a bed of flowers in her pajamas...

Human magic before the Barrier was achieved through the Cooperative Connection, a bond wherein a monster gifts his or her memories, and thus a part of their soul, to a human. Discovered when Queen Toriel gifted a blind prince a blanket which she weaved in her memories of describing the starry sky far above her castle in the Monster Capital.

our story begins with the simple question: What happens when someone take pity on the six souls and sets them free?

Hace años que los monstruos han salido a la superficie gracias a Frisk, que se ha sacrificado por la libertad de ellos. Pero a pesar del tiempo Sans no puede superar su duelo. Una día simplemente desaparece alertando a sus amigos, sobre todo a su hermano, que comienzan su búsqueda con un muy mal presentimiento.

After Chara accidentally walks into their best friend undressing whilst searching for something which was theirs, they realize that they do not feel the same way about them as they used to when they were children. Things escalate from here and they both share a night they will never forget. Neither the first time they will experience it... Nor the tenth. (Charisk lemon)

Genocide. Last corridor. Frisk with a knife in his hands, and on the contrary stands Sans. Everything is as always, but according to the law of meanness, everything did not go according to the standard development of events...

What would you rather see? A skeleton and a human talking about magic? A king thinking over his decision on if he should let humans live underground? A flower who's hellbent on killing everyone and everything? Or perhaps a young aspiring guard working their patrols diligently. The side stories of their lives, chosen by our readers, reside here. Sequel to Two Worlds, Two Souls.

After sacrificing the souls to destroy the barrier and give everyone a happy ending, Asriel stayed behind in the Underground. He feared that, without a soul, he would hurt everyone as Flowey. But when a new human falls into the Underground he decides to help her out. And during their travels the duo have interesting encounters and discoveries in the now empty(?) Underground.

A single choice has a huge impact. Not just on one person's life, but on everyone around them. In the Underground, there are many paths one can take. But when Frisk makes a choice that takes them off all the known paths, the world is changed forever, and Frisk becomes intrinsic to the fate of not just Monsters, but the whole world.

Just a short Undertale fanfic story. This story was written by a A.I chat system that someone told me about!

Before the events of Underverse begin, seven people disappear from their Multiverse. Dream, Error, Fresh, Stretch, Outer, Core!Frisk and Cross!Chara are trapped in a new world that they can't leave until they watch everything they're given. They get one chance and have to choose carefully what they change, for better or worse...

The adopted daughter of the King and Queen of monsters, a young girl who can't handle humanity, both abandoned the civilizations of their birth species, lived a century apart, now they must work together to free the Underground and allow the monsters to see the sunlight once more. But will they be able to succeed, or will a certain flower stop them? Time will tell. Charisk.

"The little girl just could not sleep because her thoughts were way too deep, her mind had gone out for a stroll and fallen down the rabbit hole." - A life of fear is not what Frisk ever expected to have. - Warning: this is a dark AU that tackles mature themes and is not recommended for sensitive readers.

Luna has heard a lot about Grillby, but hasn't met him yet. Mettaton decides it's time for his daughter to meet the fire elemental who is her uncle. Done as a request for paradise dazzleshine. :)

For Monsterkind, the Surface represented freedom. For Frisk, it's a return to some uncomfortable realities. It all began with a simple wish. When that wish faded, Frisk tried to move on. Except, 'moving on' was not so simple. Emerging from the Underground had put them in a worldwide spotlight. From an unknown child, they had become an icon of great value.

Solo era café. Su hermano le habia pedido traerle esa taza de la cafetería que tanto le había atraído durante esos días, sin embargo, termino conociendo al Comediante. Como decía su hermano, "La vida comienza despues del café" [Sans x Chara] [Chans] - Actualización 14/02/2023, Especial San Valentin

The story right after Undertale.

Mi nacimiento fue la causa de aquella ruptura, la traición infligida la hizo más grande. Los universos alternos colapsan. El tiempo termina, los seres inmortales mueren. El destino se ha sellado. El equilibrio esta roto. ¿Qué es lo que debería hacer? Ser el sacrificio, eso es obvio. Y sin embargo, "El destino es un hijo de puta." Murmuré, mientras trataba de seguir cuerdo. [Yaoi]

Break of day, the dawn is here, Anny's up and pacing. Compromise or persevere, his mind is racing. Seems like two romantically inept dorks can't confess their obvious as fuck feelings for each other What happens when they can't bottle them up no longer? Doubletale belongs to XWolf26 and Mako belongs to XRabbit

An informational guide to the traits, powers, and anatomy of human souls.

Two essences in one body, it was never meant to last. Two weeks after monsters' freedom, the unlikely cohabitation between Frisk and Chara within one body starts breaking down. Frisk's body pays the price while both of their consciousnesses slowly start blending together. As they become a kind of human amalgamate, the two begin losing themselves more and more with each passing day.

A household full of skeletons are competing over the attentions of one love. This isnt that house though. Unknown to the group secretively wrestling with their unpredictable love lives and universe-meddling machine, another house a few doors down has been gifted with its own skeleton posse clamoring for the attentions of their own little lady. A little old lady by the name of Mabel

Frisk is coming home after having been gone for a week. Papyrus can't wait to have her in his arms again. Just a fluffy little oneshot I wrote a while back and finally decided to post. Based on the Tumblr prompt "Reunion Hug."

The Rescue Arc continues with more suspense!

Tell me my friend. A story as my eyes fall, one last story of how it ends, how it begins... and once its over let my eyes fall peacefully, and then when we meet again you can tell me everything new. "Well... it all began with a tear."