From Halopedia, the Halo wiki
The Griever is an enormous, tri-hulled craft employed by the Banished. Despite its classification as a fighter-bomber, it is also referred to as a heavy bomber, and has cannon mounts large enough to be visible from more than two kilometres away. The craft is equipped with at least two weapon systems; the primary weapon being dispersion nozzles capable of spraying plasma down onto the surface and capable of "reducing half of New Mohács to glass", and a secondary armament consisting of multiple plasma cannons capable of firing "vehicle-sized" plasma bolts.
The Griever is also equipped with numerous defensive countermeasures including chaff, flares and energy shielding alongside heavy armor. The combined shields and armor are able to take the impact of three volleys each of two Anaconda surface-to-air missiles in under three seconds before failing; requiring substantial concentrated fire to down.
Grievers were employed by the Banished on Reach during Operation: WOLFE. During their occupation of Reach, they employed Grievers whenever pockets of resistance were encountered; in such events a single fighter-bomber was deployed to turn the pocket into a crater. Five such craft were later employed in an attack on New Mohács.
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