Letty Whiterock (EntityTopic, 7)
From Compile Worlds
Letty Whiterock is a yuki-onna who hails from Gensokyo. Since she hails from Gensokyo, she can shoot you in the face with pretty bullet spam. Sometimes, though, she wouldn't really be that motivated to actually shoot you in the face so brutally, so she just ends up being a Stage 1 boss, more often than not. Since she is a yuki-onna, and yuki-onna are ice element, it's easy to mistake her bullets with snow.
There are floating rumors about her so-called "weight issues" and relation with Cirno. She may dismiss these as nothing more than "rumors", but perhaps that's just her trying to keep her "secret" a "secret"... which is obviously not working.