Ruins' Dummy Doodles
The depths of this ghost's pettiness never fail to amuse me lol. Will literally send Maddie to murder Frisk no matter what you do. It's hilarious, really, I love them so much.
Now, as for the headcanons:
I call them Syle (from the word "silent") and they are Blooky's older sibling for a change, going by they/she. Their parent, Batablook, is based on Napstablook concept art because I can do anything. Every time they show their true nature, they get dramatic dark shading.
They like peace and quiet, but find Toriel's presence comforting and have taken a liking to her. She was willing to let Frisk's transgressions slide, even though she was incredibly miffed about their encounter, but then they went and upset Tori (or worse, killed her), so she is hell-bent on retribution. They could do it themselves, but they don't like getting their hands dirty. Her younger cousin can be the one to administer justice...