Comments posted to our Bloodborne Wiki
I you look above the bosses are listed per category (Enemies, Bosses, Great ones, etc.) So if you're looking for Amygdala and such, they're in the Great Ones category ^^
technically, any boss that doesn't progress the MAIN story is an optional boss
what about the abreetis sorry i don't know how to spell it
Ebrietas is optional.