The Highland Drake Dragonriding mount received a new Elementium transformation in the latest Patch 10.1 build on the PTR that drops in Aberrus.

We assume Highland Drake: Embodiment of the Elementium Drake will be a drop from the final boss of the 10.1 raid, similar to how Renewed Proto-Drake: Embodiment of the Storm-Eater drops from Raszageth.

The good news is the item should be available even on Raid Finder difficulty.