After the Merlin-powered P-63B failed to come to fruition, production moved to the P-63C. It was powered by an improved Allison engine that came equipped with water injection which could boost power up to an impressive 1,800 hp. The wing span was also shortened, but was otherwise largely the same as the P-63A. The C-5 in particular had a ventral fin to help with stability and had more armour. Over 1,000 P-63Cs were produced and delivered well into the war. Many were sent to the Soviets under the lend-lease program but around 100 were also sent to France. This specific Kingcobra isn't based on any historical aircraft but features a unique skin that resembles the scales of a snake.

The Kingcobra (USA) was introduced in Update 1.77 "Advancing Storm" as a reward vehicle for the 2018 "Flying Serpent, Crouching Tiger" crafting event. Other than the skin, the Kingcobra (USA) is the same as the regular tech tree P-63C-5. It has the same performance, offensive weaponry, and suspended armament. The P-63C-5 received an updated version of the Allison V-1710 that made a lot more power than previous Kingcobras. It also was better suited at higher altitudes thanks to the addition of a supercharger optimized for high-altitude. However, many of its opponents will be able to outperform the Kingcobra at high altitude so players should stick to low altitude for dogfighting. The Kingcobra also suffers from compression so aggressive, high-speed dives at low altitudes are not recommended.