Dead Goliath

The Dead Goliaths are two huge naga-like skeletons in the Valley of Bones in Desolace.

Lore
The Valley of Bones in Desolace is a crag infested by skeletons and centaur necromancers. Collapsed against the cliff wall are several massive skeletons, that resemble snakes or naga. They have armor and each hold a trident. Many believe that the Valley of Bones is cursed, and as such almost all of the centaur clans avoid it. The valley’s floor is littered with what is believed to be bones of the Old Gods, presided over by Magram centaur necromancers and skeletons.

Hornizz Brimbuzzle refers to the "two big skeletons in the valley" as Dead Goliaths in the quest.

The Dead Goliaths may be the mentioned Old Gods, or servants of the Old Gods. In life they may have been called "Goliaths", or "The Dead Goliaths" may be just a term for their remains.

If so, it's possible they are giant faceless ones like Soggoth the Slitherer and Sor'getha.