Alpha Jiralhanae

The Alpha Jiralhanae, also known as Alpha Brute is a Covenant Jiralhanae rank. Gargantum was an Alpha Jiralhanae. Brutes of this rank appear to be of equal rank to Elite Ultras or Zealots, as they serve as ship masters.

It is unclear if "Alpha" is just another name for one of the existing Brute Ranks (Likely Brute Captain or Brute Chieftain) or if it is an entirely different rank in itself.