This is a mug shaped like a skull wearing a Spanish conquistador's helmet. This first edition was glazed in a variated rusty brown glaze.
From Lost Temple Traders:
"The Last Conquest is a collaboration between Lost Temple Traders and Trevor Foster Studios. Limited Edition (Max 300. We’re doing this pre-order to see if there’s enough demand to increase the run from 200 because there were a lot of people disappointed with the quick sellout of the test pilot). The skull holds 24oz, and the helmet functions as a lid. Expected Ship Date Q4 2022."