Emmon Cuy

A member of Renly's Kingsguard is an unnamed background character in the second season.. He is played by an unidentified extra and only appears in the "The Ghost of Harrenhal." He is killed by Brienne of Tarth after he blames and attacks her in the wake of Renly's assassination.

Season 2
King Renly Baratheon's camp is a hive of activity as his troops prepare for the coming battle with the forces of King Stannis Baratheon in darkness. The camp is beset by strong winds. Catelyn Stark meets with King Renly in his command tent. This Kingsguard and one of his sworn brothers are outside while Brienne of Tarth stands watch inside the tent. Hearing Brienne scream the guards rush into the tent with swords in hand. They see Brienne kneeling over Renly’s corpse and assume that she is responsible. They threaten her life. Catelyn tries to intervene but they push her aside. Brienne fights both of them off, killing them.

In the books
In the Song of Ice and Fire novels, Ser Robar Royce and Ser Emmon Cuy arrive just after Renly's assassination. Cuy blames Brienne for the death and attacks her. Catelyn Stark convinces Robar that Brienne is innocent and he fights off the men-at-arms that follow Cuy.