henry not dropping rare loot?

[MeltedBananaTaffy]

trying to farm henry for the "i cant breath in this" head for krieg
ive been told its capable of dropping a head customization for any class, and somehow after farming it for like 10 minutes straight it hasnt dropped any of them
it has however dropped the cradle, so it doesnt seem like its just incapable
is there possibly some requirement im not meeting? or am i just impatient

[Renfrew]

The issue with Henry is the same issue many bosses with multiple dedicated drops have. In short, the drop chance is 10% and that is split across the items, I can't recall whether it is split evenly amongst the items or if it is ratio'd. In other words whether your chances of getting a particular item is 1/7 from that 10% (because there is the cradle and 6 heads) or if the chances are 1/2, as it might consider the Cradle and the Head as two separate items before applying parts (in the case of the head, deciding which character it is for), and that would mean that 5% is split across the 6 heads.