You need to be more specific about "bosses" and "special creatures". What is a "special creature" for you? Is the Black Knight a special creature (it's not a boss)? What about Crustacea Giganticas, which can spawn in raids or in varying monster homes (also not technically bosses)? I suggest you be stick to, let's say, creatures in the bestiary that aren't very rare, which is a very well defined group.