Gorbag

Gorbag was a Captain of Orcs in Minas Morgul. Slain by Shagrat in T.A, 3019 in a bloody quarrel over Frodo's magic treasures — the Hobbit´s mithril shirt, elvish cloak, and magic sword — he was a victim of his own greed, as well as the tendency for Orcs to settle disputes with force. When Gorbag and Shagrat fought, both their companies suffered dearly, and the quarrel ended with many Uruk-hai slain, Gorbag had a lot of grit and could stand wounds for a long time, but he was too slow when it earne time to strike.

speculations
In the Books both, Shagrat and Gorbag, consider themselves Uruks.In the Movie trilogy however Shagrat is obviously a huge Uruk-Hai while his counterpart Gorbag rather resembles a lesser Fighting-Orc (though possibly he was just an older somewhat smaller and crooked Uruk too).