Gothmog

Gothmog was the lieutenant of the Witch-king in the Third Age from Minas Morgul, notably serving at the Battle of the Pelennor Fields.
Gothmog was mentioned at the Battle of the Pelennor Fields, following the loss of his master: in response to the arrival of the Rohirrim, he called his army's reserve out of Osgiliath and into the main battle, and brought Easterlings, Southrons, Variags, and Troll-men "into the fray".
He is first seen commanding the Orcs crossing the Anduin river to the western half of Osgiliath, which was still held by Men, and orders the first shot fired in the Battle of Osgiliath. After Faramir's retreat, a second legion enters the city from Minas Morgul via the bridge that the Orcs who controlled the eastern side of the city had rebuilt.
The troops of Gondor retreated, leaving behind their wounded, one of whom is Madril, the badly-wounded captain of the Ithilien rangers, whom Gothmog kills with a spear. The Witch-king, arrived from Minas Morgul, then instructs him to assault Minas Tirith using all legions at his disposal. When Gothmog asks about Gandalf, the Witch-king replies that he will "break him".
When Faramir rides out with a small band of Gondor Knights on horseback, attempting to retake the city, Gothmog orders his archers to fire a volley from the ruins of Osgiliath which kill the knights save Faramir. Once his forces arrive on the Pelennor Fields, he orders the heads of the dead soldiers in Osgiliath to be launched off the catapults, to instill fear into the hearts of Gondor's soldiers and destroy their morale.
Gothmog then begins directing the main ground operations, from catapults to siege-towers. He becomes enraged when the doors into the city won't budge, ordering Grond to be brought forth to smash it down. When the defenders of Gondor start launching debris at the attackers with trebuchets, Gothmog orders his troops to hold still. When a large piece of the debris is launched directly at him, Gothmog waits until the last second before sidestepping to avoid it by about a foot, prompting him to mock his opponents by spitting on it. His lieutenants are Guritz, with the skull on his helmet, who seemed to be the siege commander, and Murgash, a Black Uruk.
In the theatrical release, Gothmog is presumed dead after the Rohirrim's charge as he is last seen trying to back away as the Rohirrim kill his men.
In the extended edition, he is shown to have survived the onslaught and duels Éowyn, who gains the upper hand and wounds his leg. Gothmog collapses in pain moments before the Witch-king arrives on the scene of the battle. Éowyn succeeds in destroying the Witch-king, but is injured in the process and crawls to Merry.
At this point, Gothmog rises, furious for revenge, and uses an axe for support as he limps towards her. As he approaches, he discards the axe and picks up a mace, preparing to kill Éowyn. Aragorn rushes in and chops off his arm, before Gimli strikes Gothmog from behind in the torso with his axe, and Aragorn then delivers the final blow to his back, killing him.