Greasus Goldtooth - or, to give him his formal title, Tradelord Greasus Tribestealer Drakecrush Hoardmaster Goldtooth the Shockingly Obese - is the closest thing that the Ogre Kingdoms have to an overarching ruler. A big and powerful ogre, Greasus was destined for more because he had something few other ogres do: a brain big enough to consider things beyond bludgeoning to death whatever was at hand and then eating it.
His name is a reference and a pun, mixing "grease" with Croesus, the legendarily rich Lydian King who fought the Persian Empire.
After killing and eating his father Gofg, formerly infamous Tyrant of the Vale of Titans, he decided he wanted to be boss of all the other ogres around too. First, he buried one tribe that refused alive by starting an avalanch above their holdings when they were all inside for the Great Feast of Midwinter. Come the spring solstice, he approached the tribe of Gut Badmouth to challenge the Tyrant to a guts out pitfight for the tribe; cunning as always, Greasus let the much bigger and stronger Tyrant clamber down into the pit first, then bellyflopped onto him from the pit's lip and broke his neck. There was some dissent as to whether this was a "legit" win, but after he beat and ate three dissident Bruisers in a row, everyone else shut up and followed him.
Since then, Greasus has become the number one power in the Ogre Kingdoms, collecting tithes from all the kingdoms along the Silver Road (i.e. Fantasy Silk Road), so huge and rich that he no longer walks but is instead carried everywhere by grunting, straining gnoblars. He carries a big scepter that is also a super-club that grants him the strength of a sky-titan, and wears a magic crown that enhances his already-sharp intellect to near-human levels. Said crown was created by the best magic users and blacksmiths of the Empire, who were actually commissioned by Greaseus to create such a relic.
When every volcano in the Mountains of Mourn decided to erupt, Greasus took the prudent route and decided a new ogre migration was needed. So he gathered every tribe and began the march westward. At one point, the Ogres collided with Waaagh!Grimgor, and the two belligerents began the last Orc vs. Ogre war. Though Grimgor had the numbers, Greasus commanded the largest army of ogres the world had ever seen. The war drags on until Grimgor and Greasus meet on the battlefield, both wanting to test their strength against the others. They duel for hours, Greasus' club giving him the strength to match the incarnate of beasts blow for blow. At the end, Greasus disarms Grimgor and is about to win, but lets hubris get the best of him. Tossing his club aside, he tries to pick up Grimgor and squeeze the life out of him the way he did to the last black orc war boss he fought. Instead, Grimgor avoids him, picks up the scepter and smashes in his skull. With this, the last of the Loyal ogres abased themselves before Grimgor and the ogre kingdoms as a nation were no more.