Jamargar

Jamargar was a lieutenant of Varharran during the Shatterwar. His main achievement of note was slaying the Eladrin King Kelvoras, leading directly to the goddess Dialiah's now infamous curse that "For a thousand years, nothing will survive your footsteps". This lead to the desertification of Urruk, which in turn was the catalyst for the formation of the modern (badass) Orcs. Jamargar is therefore perhaps the most influential Orc in history.