Bad Dream (Undertale/Gravity Falls OC Crossover)

Tonie Crypt, a half Dream Demon, half human hybrid, finds herself in an underground world filled with creatures she's only seen in one other place, Gravity Falls, Oregon. But that doesn't matter, this place was far from that small and weird town. She was miles underneath the surface of the earth, and left alone in the dark. That is until a small voice speaks to her, telling her that in the Underground, it's kill or be killed. But that voice soon finds out that there are creatures in that world that are not so willing to abide by that rule. Tonie soon gets saved by a large, human-like goat, who brings her deeper into the catacombs. But as she stays there, the more and more she wants to leave. Will she be able to get free from this place? Or will she be forced roam aimlessly forever. Tonie will be finding friends and foes, and even in between. But again, will she ever be able to escape?

Disclaimer: In this story, Tonie Crypt will be running a Pacifist run. This is so I don't have to write about possibly having to kill my Sanspai.