B-ko? from Project A-ko? (not that I've ever seen it but)
and yup, I like obake and youkai a lot, I've been wanting to make one based off a futakuchi-onna but here it's mostly just experimentation that I'm not sure if I'll apply to the final character here.
Link
Gonechoo
There's this ever-so-faint 'B-ko' vibe to her.