Underfalls: A Gravity Falls/ Undertale Crossover

Underfalls: A Gravity Falls/ Undertale Crossover

29.6K Reads 964 Votes 13 Part Story
Ally the Trash Bin By Marshmewwos Completed

"Dipper, there is one last thing to prevent Bill's reign of terror for good. You must climb to Mt. Ebbot, not far from here, and retrieve some inter-dimensional travel-block. It will prevent Bill from ever crossing into our realm, and taking over our world."

"Ok Great Uncle Ford. I'm on it-"

"Oh and Dipper?"

"Yes Great Uncle Ford?"

"Take Mabel with you. Its dangerous to climb Mt. Ebott one. Legends say that those who climb the mountain never return. Be careful Dipper,"

"I will. Thanks Great Uncle Ford."


Dipper and Mabel Pines are your average twins, spending the summer at their "Grunkle" Stan's Mystery Shack. But, as the summer progresses, Stan's twin brother, Stanford, returns. Bill, the evil inter-dimensional mastermind plans to cross over into the world of Gravity Falls, and the apocalypse of "Weirdmageddon" draws near.Then the twins are forced to Mt.Ebott, where theyll do the unthinkable...

  • alphys
  • crossover
  • dipper
  • flowey
  • gravityfalls
  • mabel
  • papyrus
  • sans
  • toriel
  • undertale
  • undyne
SamGamer_1542 SamGamer_1542 Aug 02, 2017
Theres a line you missed, something about him saying that someone needed to teach them how things work.
Rude_Baby_Red Rude_Baby_Red Aug 20, 2017
Because Froggit didn't understand what you said but was flattered anyway. ;)
- - Mar 09, 2017
                              This story contains sencs of stupidty, Gravity Falls, fighting, and some more sanspai for the fan girls.
                              READ AT YOUR OWN FRISK. I MEAN RISK.
SmolFanGurl40 SmolFanGurl40 Dec 31, 2017
Don't worry I'll spot them and laugh and the newly found word to invent like fre sh a voc a do was invented
Radical_Jasper Radical_Jasper Aug 09, 2017
Oh leave the 12 year olds to climb up a mountain where people never return! MAN THIS GUY REALLY IS A GENIUS!!
                              *Sarcasm levels at 100%*
Trash_Panda_Raycoon Trash_Panda_Raycoon Aug 29, 2016
So they just don't question the weird text boxes that appear.