Misery from Cave Story for Pony Diffusion.
Recommended strength: 1
Trigger word: csmisery
Clothing: turtleneck, crop top, pants
Likes to generate bare feet about half the time, so just specify shoes if you don't want that
Note that due to Misery's androgynous clothing, this model may attempt to generate a male version of the character. Usually the trigger word is enough to avoid this, but if it's not, try (1boy, man) in negatives and that has worked for me every time. "crop top" is associated with women enough that usually also shocks it out of trying to make her male.
I find this one to be a bit challenging to work with overall; cave story has a weird art style and a lot of the art of her online is at least partially reminiscent of that.