Gargantum

Gargantum was a Jiralhanae Chieftain and Ship Master of the Covenant Frigate Twilight Compunction.

He was aboard his ship during The Battle of Installation 05 and when the Civil War of the Covenant broke out, he took control of several other Brute-held ships in the Second Fleet of Homogenous Clarity and brought them to attack the Elite held ships. His ship, along with the Tenebrous, tried to attack the Elite-held Incorruptible, but the attack was stopped when the Tenebrous was destroyed by the Incorruptible and the Twilight Compunction was attacked and damaged by the Elite-held Carrier Lawgiver.

Gargantum's ship, along with the Reverant and another frigate, followed the Incorruptible as it tried to escape. When the ship Bloodied Spirit dropped out of Slipspace nearby, Gargantum hailed it and discovered it was controlled by Spartan-IIs. He sent one frigate to attack it, but while his forces were divided, the Revenant was destroyed by the Incorruptible. Gargantum then took his two remaining ships to pursue the Bloodied Spirit.

Trivia
Interestingly his name does not contain the "us" suffix that signifies adulthood.