The UNSC Cumulus (UNSC Cruiser C597) was a United Nations Space Command Halcyon-class Cruiser in service from 2525 to 2550. Helmed by Devin Briggs, the Cumulus was fitted with heavy weaponry and an advanced AI to assist it with strikes against Covenant battlecruisers. It later became the flagship of Ninth Fleet and led many defensives against the Covenant in the outer colonies. When the outer colonies fell, the Cumulus became part of offensive attacks against Covenant forces occupying UNSC territories.