The Cobra-class destroyer is one of the smallest battle-worthy ships in Battlefleet Calixis, with a main hull measuring a little over 500 meters in length (the forward 'beak' and plasma baffles are in addition to this). As a military ship the Cobra is filled with all kinds of systems and ordnance, making the vessel feel compact and crowded when compared to larger ships. The Cobra is a tried-and-true STC pattern that is relatively simple to produce - many of Calixis cobra as produced in-sector.

The Cobra-class is a fast torpedo carrier. Armed with massive anti-warship torpedoes, squadrons of Cobras are fast and agile enough to dart into fleet engagements, launch spreads of heavy ordnance, then retreat in good order. The Cobra has rather weak void shielding - it's massive engines eat up most of the energy its solar generator can produce - but its compact hull is well armored. Since Battlefleet Calixis is short on battleships the Cobra is a very important part of all Calixian fleets - working with Lunar-class cruisers the Cobra the primary weapon employed against enemy battleships.