I love Undertale. But, while I was stuck on figuring out what story to write that hasn't already been written, I found a delightful inspiration in an AU freshly created by the deviantartist BamSaraKilledYou (bamsarakilledyou dot deviantart dot com). All credit for the idea goes to her, and this story is created with her permission.
Anyway, on with the story!
Long ago, two races ruled over Earth: HUMANS and MONSTERS.
One day, war broke out between the two races. After a long battle, the humans were victorious. They sealed the monsters underground with a magic spell.
Many years later… Mt. Ebott, 201X
Legends say that those who climb the mountain never return.
It was an ordinary day underground. Night, maybe? Who could really tell? Well, except for one spot. In the innermost part of the Underground, there was one chamber where the sun's passing could be seen by a beam of light coming from the hole above. Monsters still could not cross, because of the barrier, but it was nice to have. Especially for one creature in particular, the chamber made a great napping spot with the gentle warmth provided.
Napping in the room was a white dog. He seemed to be a larger than average American Eskimo dog with dense, fluffy fur. Perhaps being underground had some sort of effect on his growth. He snored gently as he was curled up on the bed of flowers. When a stick fell nearby, his ear twitched and his head rose as he looked at the fallen stick, tilting his head curiously.
The dog looked up and noticed a small shape falling rapidly toward the flower patch he was laying on.
The figure fell on the flowers right next to the dog and he jumped away as petals were thrown into the air. The dog returned to the spot where the figure had fallen and looked closer before taking a sniff. It smelt funny! Didn't smell like anyone he'd smelt in the Underground. Was this one of those humans he'd heard monsters talking about? It was a lot smaller than he thought one would be! It must be a lost puppy-human!
The dog looked at the stick. Was that theirs? The puppy started groaning as their face shifted among the flowers. They'll probably want their stick back. He trotted over and grabbed it in his teeth before returning to the puppy right as they looked up and rubbed their head.
The puppy seemed surprised that there was a dog right in front of them, and when he dropped the stick on the flowers in front of him, they looked between him and the stick. He sat down, waiting as the puppy took up the stick and held it up.
"Do you want the stick?" they asked as they waved it.
The dog was excited by the waving and wagged his tail. Fetch? He loved fetching!
The puppy threw the stick and he ran to go catch it as it bounced off the wall of the chamber. He caught it out of the air and returned to the puppy's side. The puppy scratched him behind the ears and he rolled over, allowing them to rub his belly.
The puppy laughed, saying, "Can I call you Toby?"
The dog's tongue lolled out of his mouth. Toby sounded nice, but as long as the puppy rubbed his belly every once in a while, then he'd be fine with whatever name.
"Arf arf!" Toby barked. "[What's your name?]"
The puppy smiled, but didn't answer. Could puppy-humans not understand dogs?
"Ruff," Toby barked. "[Wait here.]"
He ran off and phased through the wall. If he could get his bark-to-English translator from home, things should be much easier.
Frisk watched with raised eyebrows as Toby left through the wall. Maybe Toby was more than just a dog. He was pretty big for one.
Their head sagged. It had been nice to have some friendly company in this strange place. Maybe they'd meet Toby again. Looking around at their surroundings, Frisk saw that there was only one path forward. They took up their stick. Maybe they'd have a use for it later.
Filled with determination, Frisk moved forward to see what there was in this underground cavern.
Once they went through an ancient looking doorway, they were struck by a strange sight. A flower with golden petals on a stem without any leaves. But the strange thing about it was that the flower had a smile on its face.
Even stranger was that it started to talk, the mouth smiling in a cheery manner, "Howdy! I'm Flowey! Flowey the Flower!"
Sorry for the stubby prologue. I'm not sure when I'll be able to update this story, but I'll find time.
See you when I see you.