SP42 Cobra

The Special Purpose-42 Main Battle Tank, commonly known as the Cobra, is a hybrid anti-matériel and anti-fortification vehicle built by Misriah Armory. It was adopted into Colonial Military Authority (CMA) service in 2497, though most units were eventually transferred into United Nations Space Command (UNSC) control during the Human-Covenant War.

Chassis
Despite the Cobra's classification as a main battle tank it is designed to be lightly armored, fast, and maneuverable. Unlike most tanks the SP42 uses six all-terrain wheels that enable impressive mobility even over rough terrain and are protected by pivoting front and rear wheel guards. The two rear wheels are retracted when the vehicle enters lockdown mode.

Armament
Unlike most UNSC vehicles the Cobra fills two distinct roles: that of a mobile anti-matériel platform and that of a self-propelled artillery piece. The SP42 MBT is equipped with a pair of turret-mounted M66 30mm light railguns that fire high-density ferrous slugs; these slugs are twice the size of those used by the M68 Gauss cannon and are designed to penetrate enemy armor using sheer kinetic energy. The railguns fire intermittently, not in a single burst, as the energy required to accelerate the slugs to the speeds required to pierce the heaviest armor can only be managed for one of the cannons at a time. Synchronized fire from both railguns can destroy even the most heavily armored tank, with penetration that easily outguns the M808 Main Battle Tank's standard M512 90mm cannon.

In addition to the Cobra's anti-vehicle role the tank can be stabilized upon the ground, "locking down", and deploy an M98 105mm light railgun which fires a conventional explosive shell at supersonic velocities. The explosive and kinetic forces of the shell complement each other to increase the damage inflicted. An M98's shell, when specially outfitted, can penetrate a 's energy shield and destroy the platform; a single shot can likewise disable the shields occasionally outfitted on the  and deal minor damage to the hull. Massed fire from several M98s can quickly destroy even a Covenant citadel, a massive structure outfitted with starship-grade armor plating.

Service history
The SP42 Cobra was first deployed in 2497 during Operation: CHARLEMAGNE, as a supplement of the M808 Scorpion. The UNSC later inherited most Cobras from the CMA during the Human-Covenant War, but would not continue their production.

Gameplay
The Cobra can be produced at the Vehicle Depot for 350 resources, two population slots, and if the player has a tech level of 2. It has the following upgrades:
 * Deflection Plating - Gives the Cobra extra protection. Cost 400 resources.


 * Piercing Shot - Enables railgun to penetrate multiple targets, damaging each. Cost 900 resources.

Trivia

 * Like most UNSC vehicles the Cobra is superficially similar to its animal namesake. When locked down the SP42 MBT lowers itself and becomes poised to fire; this is similar to actual cobras, which typically coil before striking. The vehicle is especially similar to the spitting cobra, which can project venom to great distances.
 * The Cobra's artillery mode has an uncanny resemblance to the Terran siege tank from Starcraft, which can transform from tank mode to siege mode, with a sacrifice of mobility for longer range and greater firepower.
 * Despite its designation as a main battle tank, the Cobra is technically a hybrid self-propelled gun and tank destroyer. The "tank" moniker is likely an in-universe misnomer or simplification, as with the M9 Wolverine.

List of appearances

 * Halo Wars