M808 Scorpion

The M808 Scorpion main battle tank, also known by the Covenant as the Crawler, is the primary main battle tank (MBT) used by the UNSC Army and UNSC Marine Corps. It replaced the M801 Wolf Spider MBT.

M808A
The initial production model of the Scorpion suffered from engineering failures with its track motors which could be bricked if one its tracks was damaged, nullifying the point of its quad track setup. Its fuel storage was unusually small, which would be increased with all later models. The turret was designed to by highly modular, with space for remote weapon stations, additional armor packages, extended ammunition magazines and additional coaxial weapons, however the turret drive was known to not be handle the stress from the extra weight and would breakdown frequently without third-party modifications.

M808B
The B modification featured an entirely new turret that was shorter, had a reworked auto-loading mechanism that made ammunition type switching less prone to jamming, and snappy traverse and elevation drive. The commander's position received a machine gun that could be used when he peaked out the vehicle, though this was of questionable value and was often removed by the vehicle's crew. The reworked turret also made modification and re-gunning easier - with M808Bs being known to mount larger 105 and 120mm guns during the Human-Covenant War.

M808B3/M911 Tarantula
MLRS variant mounting twin Scimitar 40x178mm hypervelocity rocket pods in place of the main gun. Limited success.

M808C
Entering service during the Insurrection, M808C was one of the last production runs of the Scorpion tank. Notable differences are a more angular turret, newer armor composites for added protection with moderate reduction in maneuverability, and a further reworked autoloader system to prevent jamming during shell ejection.

M809 Sun Devil ADS
A short range air defense vehicle based on the Scorpion hull. The turret houses four 40mm auto-cannons and radar for search and track of aerial targets. The M809B is wartime modification with supplementary 65mm Argent V anti-air missile pods.