Aggo (The North Remembers)

"Rakharo, Aggo, Kovarro. Take our remaining horses. You will ride east, you southeast, you northeast."

- Daenerys Targaryen, addressing her three bloodriders in turn

Aggo is a background character in the second season. He is played by an unidentified extra and debuts in "The North Remembers." Aggo is a Dothraki warrior sworn to Khaleesi Daenerys Targaryen. He is one of her bloodriders.

Background
Aggo was a member of Khal Drogo's khalasar and a member of Daenerys' khas. When Drogo's khalasar fractures, he remains loyal to Daenerys. He pledges his fealty to her after the birth of the dragons. She names his as one of her bloodriders alongside Rakharo and Kovarro.

Season 2
Daenerys leads what remains of her khalasar deep into the Red Waste. Facing starvation she sends Rakharo, Aggo, and Kovarro to scout in three different directions, using the last remaining horses. Aggo is sent southeast.

In the books
In the A Song of Ice and Fire novels, Aggo is one of the three bodyguards of Daenerys Targaryen and is named both ko and bloodrider after she hatches her dragon eggs. He's an adept archer who saves Daenerys' life from Cohollo, one of Drogo's bloodriders.

Following Khal Drogo's death, Aggo and the other two bloodriders Jhogo and Rakharo are among the few who remain with Daenerys. Before entering the funeral pyre, Daenerys gives Aggo the dragonbone bow that was her bride gift and names him her ko. Aggo accepts the bow with lowered eyes, saying "I cannot say these words. Only a man can lead a khalasar or name a ko." However, once Daenerys comes out of the pyre alive and with the born dragons, Aggo is the second of the bloodriders to declare "Blood of my blood", and since then he is totally loyal to Daenerys.