suggestions in Undertale MULTIPLAYER
Use your imagination!
VENOM SANS. VENOM FUCKING SANS
and please please please add grillby stupid post right
i suggest this what about story spin or storyswap and glitchtale my personal favorite inverted fate please add these last two please :)
@aloh4 
what about making an secret rooms and making an character that let players play with it all the game
what you choose your character at the start and you keep that character for the rest of the game [excluding sans, toriel, asgore, papyrus, undyne and the AU's of them]