Reader insert. What if W.D Gaster didn't just get split between time and space, but actually ended up in your world in an abandoned hospital you called home? Your were a young child he decided to use as experiments to test human determination in said world and breaks physical laws to test human possibility? He knows of the powers you gained from his experiments... all but one, this one allows you to tear realities just enough to teleport into them. Knowing of Undertale you felt bad for the monsters stuck below in their world and wish to help them, but something goes wrong and you end up going to certain AUs and helping them, gaining the attention of some bad skeletons who now desire your power for them-selfish-selfs.

A girl (y/n) dies from a car crash. She thinks she's dead but ends of waking up in a snowy area as a skeleton, but not just any skeleton. Her own sans au. (This is my first book it might not be the best) (Grammar may be a tad bit off)

Cold. Everything was cold. And dark. I was so alone... how could I have wanted this? This couldn't possibly be better than before... the warmth, and the light, and the smiles, however scarce. I cried out. I screamed, but it was muffled. I wanted it back. I wanted everything back. I regretted my decisions, my plans, my dreams. I wanted a second chance. **Reborn as a ??? Sans**

The reader wakes up to a new life as a monster skeleton. In a new world, that's filled with monsters, humans, and magic. But instead of living their new life to the fullest, they will have to survive Gaster's experiments and war with humans. Just because Asgore became mad for absolute control over his citizens and the humans. Will the reader and his brothers find their freedom and a place to call home or die trying?

Slice of life and adventures with Melati!sans and his loyal companion Jasmine, together they will travel across the Multiverse as traveling Merchants. what will they find? Or what trouble they came across? You can read it to find out! - Melati!sans by me/Firuz - Undertale AUs and Sans aus

What happens when a chaotic human gets reincarnated into Hate! Sans their favorite but it proves more to be a challenge since they got reincarnated into Underverse where Nightmare is a b--ch, Error isn't forced to deetroy by Fate and more. But on the plus side atleast they can't get hurt by any physical and magic attacks unless they want to and positivity doesn't hurt them but only annoys them and they still got the memories from their past life so atleast they'll know everyone's weaknesses, strenght, fear and past- Also their emotions from their past life got muted so now the only thing they can feel is hatred and hate but sometimes they'll be able to feel other emotions but it'll just be very faint- And they just realized that they're OP since nothing can hurt them, positivity doesn't hurt them and they can also serve as a power boost for Nightmare- so yeah- And what happens if they meet Nightmare but not as Hate but as another form that they gained from a diety who reincarnated them as a gift. Will Nightmare notice that they're not what they seem or no? Will Hate join the Bad Sanses? Will Hate's secret be revealed? Will The Star Sanses find out about them? Wiill they interfere with the original storyline in Underverse? Will Hate help Cross restore his AU? Will they cause chaos for everyone?(Spoilers: They do-) Will Ink have trouble dealing with Hate? Will Hate hold back their true potentiel from everyone? Find out in this book! Ps. Hate does not have any gender in this story so their pronouns will sometimes be He/Him, She/Her or They/Them.

what if nightmare never became corrupted by the dark apple? what if he realized his brother wont help him at an early stage of life when he was bullied? what if... he changed Identities?. °----------------° then welcome to Changing identities AU! this is a half story and half oneshot book!{maybe} of course depends on my motivation. anyway, this story as it suggest will have mature themes. as such- ' Murder ' Kidnap ' Bullying ' Gore [hopefully abit in the further parts] ' Stalking ' Nootnoot why- [Basically Yandere] Ill add as the story progresses And ship too added in. story status; LOOKING FOR ADOPT

You are an odd person, you don't really remember your own backstory Weird right? Well you begin to see an odd figure in your nightmares. You shrug it off at first but as they say SOME NIGHTMARES ARE MORE REAL THAN OTHERS

First off, where am I? Did I get kidnapped or something? Wait a minute- is it just me or do I look like bones? Also what's with the two big paint brushes with me and why do I feel as if I have two extra limbs on me?