Hello my babies! Now, for those of you who may be wondering why I've started a new story, it's because I was insanely inspired to write after being on Pinterest for 7 hours straight. Along with this story, which, if you couldn't tell, is from the Monster Falls AU, I will be updating Winchester Falls in a little while possibly shortly after I post this story) and writing TWO MORE new stories. The first new story, for those interested, is a Supernatural and Undertale crossover., the other being an Undertale AU story (PM me if you'd like me to write for one specific AU). So, those are the things to be on the lookout for in the future, as well as possibly (maybe not, I haven't decided) an update on one of my other stories. Check my profile for a poll on which old(er) story you would like me to update, if I so choose to do so! I'll be seeing you all soon! Thanks and Enjoy!

The Forest Surrounding the Mystery Shack - Midday

Mabel had found the small, shallow pool just an hour earlier, and insisted showing it to Dipper. The whole time she had lead him out there, he searched the journal for anything regarding the crystal clear pond. There was a small note about it being a watering hole of sorts for the fantastical beings of the area, but not much more. Dipper looked up to relay this information to Mabel, before noticing his sister was slipping her shoes off.

"Mabel! What are you doing?" He raced over to her, carefully putting the journal back into his bag.

She grinned broadly. "I'm going swimming. It's a nice day, and this water is the perfect temperature!"

Dipper looked at her in horror as he realized she must have put some part of her body, most likely a toe or finger, in the water to test it.

"Mabel, this is a watering hole for the..." He just paused, hearing a cracking branch in the distance.

Mabel looked up, hearing it as well. "Dip?" She whispered, slowly going to him, and catching her hand in his.

A crack of lightning and thunder sent the two back home, Mabel hopping as she put her shoes on. Dipper sighed, not knowing how to begin with Mabel. She decided, even after their weird experiences in Gravity Falls, to stick her hands into a strange body of water in the forest. He didn't say anything to her, though, as she seemed to be fine. Nothing had happened immediately, so what could be the immediate harm in her checking out the water alone?

It can't be so bad, right? Dipper thought to himself, pushing away his concerns for the moment.

Back at the Mystery Shack - That Night

The trees outside of Dipper's room brushed carefully against the window, causing him to stir. In the dark their voice seemed to whisper to him. It called for him to join them. He, unconsciously, walked to the direction the voices led him. A bright, golden light wrapped him in its warm embrace. It consumed his form, entangling him, soon lulling him to a deeper sleep. The warmth of the golden light enveloping him, making him feel calm and relaxed, as if the light was changing his entire being from anxious to c-

THUMP BANG CRASH!

Dipper sat up in his bed, wiping his still sleepy eyes. He looked around, seeing that Mabel was out of bed, and wondered what had fallen and woke him. A soft, moaning cry floated through the house.

"DIP! I THINK I NEED A LITTLE HELP!" shouted his sister's voice from the bathroom.

Dipper began to get up, feeling heavier than usual. His mind told him it was just from waking up so suddenly. He yawned and stretched, feeling his ears twitch as he did so, and the soft swish of his tail as he readjusted.

TAIL?!

Dipper sprang from bed, clumsily tripping over his hoofed feet. He looked back to see that, in place of his usual two legs, were the four legs and body of a deer.

"GAH!" He screamed, falling back as he attempted to get away from his own behind.

He looked towards the bathroom, thinking of Mabel as he did. If this is what happened to me, then I hope Mabel's okay!

With the thought of Mabel being in the same state as him, he staggered to the bathroom to see his sister laying in the bathtub, full of water, holding a towel up to her top. A long, purple mermaid tail had replaced her legs, shimmering in the light of the bathroom.

"Uh, I think something's wrong. A little help?"