Gagaw was part of Yayap's original Grunt unit and a good friend to Yayap. The unit was normally sleepy and saw little action but they were sent to attack the Pillar of Autumn when the vessel entered space around Installation 04. Yayap, Gagaw and three other Grunts were walking through the corridor when they spotted the barely alive Elite Zuka 'Zamamee lying on the ground wounded, who was actually injured by John-117. Gagaw was at first apathetic toward the larger alien, but Yayap convinced him to help drag 'Zamamee back to the ships. Gagaw helped convince a Covenant Intrusion Vehicle pilot to bring Zuka back. After Yayap finally convinced the pilot, the boarding craft left the ship, along with Gagaw and his team, to land on the Installation where 'Zamamee could be treated. The Grunts rescued 'Zamamee so that they would not have to fight.
Later, when 'Zamamee comes to find Yayap, Gagaw is the one who tells Yayap he is needed. However, 'Zamamee did allow Yayap to say goodbye to his friend Gagaw before he left.
He was never seen again, but he was likely killed when Installation 04 was destroyed.
- Halo: The Flood (First appearance)