Goliaths of Gorgrond

The first two world bosses will start spawning as Highmaul opens up on Dec 2nd. These bosses will both drop 650 gear and only one is up each week.

A little bit of information according to Dungeon Journal:

Tarlna the Ageless
It is said that before Tarlna arrived in Gorgrond, the entire region was a barren wasteland. It is said that verdant life springs up in the wake of each footstep of the ancient genesaur. It is said that the creature is immortal, renewed like a forest in the aftermath of a great blaze. Much is said of Tarlna, but little is truly known of understood.

Drov the Ruiner
Drov was called Ruiner by the Blackrock clans of old, who quickly learned to give the fearsome magnaron a wide berth. Drov carves a swath of devastation where he walks, as though the earth itself senses his arrival and parts to make way.