Giant Octopodes
Farmer
Funny thing is how random the items are which just don't pop. I actually found multiple aquamarines and copies of Scroll 3 while playing yesterday, but I know the feeling, it's always something! Once it was the Anchor, last playthrough my wife and I did we got to floor 100 multiple times and spent half a year digging in the skull caverns before we got our second prismatic shard and I got to upgrade from the Lava Katana XD I'm sure you'll find what you're looking for eventually!