I fluffin' LOVE this AU!!!
So, Imma go roleplay it!
I'll be Gaster Blaster Sans, and you can be whatever character you want; even ocs! And regular Undertale/AU characters, of course!
Prompt...! (I HAVE A PROMPT THIS TIME YAY)
You and Sans were hanging out in Snowdin. Sans has been acting... strange, lately. As his buddy, you wonder what to do about it.
WARNNING: BODY HORROR AND STUFFS.