From Halopedia, the Halo wiki
Mission aboard Mona Lisa
Ayad, though normally part of another squad along with Maller, was assigned to serve in Sergeant Zhao Heng Lopez's squad during a mission to investigate the prisoner transport Mona Lisa in Installation 04's debris field. According to the Red Horse's AI Rebecca, the mission was a simple reconnaissance operation; the Marines were not informed of the fact the Office of Naval Intelligence had been secretly researching the Flood on the Mona Lisa.
Upon boarding the Mona Lisa via its cargo bay using a Pelican dropship, the Marines were immediately engaged by several unarmored Covenant Sangheili. Ayad then joined Lopez's team as they went to search for Rabbit, who had gone missing. After discovering what was left of Rabbit, the Marines received their new orders to purge the Mona Lisa's navigation databases. When they proceeded to split into two teams, Ayad was nowhere to be found. He would later return as a Flood combat form, attacking Lopez's team as they approached the ship's bridge. Lopez first shot the Flood form in the left shoulder, which knocked it off its feet, but it went on toward them on all fours, before a Flood-infected Sangheili appeared and momentarily used it as a meat shield. It then dropped the Flood-infected Ayad, who soon recovered and attacked the Marines again, throwing Singh against a wall and snapping Percy's neck. MacCraw then shot the Flood form Ayad had become in the head, killing it.
Along with a number of other Marines, Ayad is not present in the motion comic adaptation of The Mona Lisa.
List of appearances