Almost every voyage, every hoard quest, every random skeleton captain (ashen and the skeleton missive) drop these skulls.

Where's the real loot out there?
I know the lesser skulls get rarer as you level up, and the skulls give good money when you have a couple dozen of them. But do we really need to be getting more and more of these skulls everytime.

Even the 3 new skeleton lords drop these skulls. You'd think they would drop their own heads, with the fancy new skeleton beards and wigs. But nope.