The Supermarine Seafang was a British Rolls-Royce Griffon-engined fighter (and later trainer) aircraft designed by Supermarine to Air Ministry specification N.5/45. It was a further development of Supermarine's famous Spitfire and Spiteful aircraft, becoming "a Spitfire too far."
The Seafang was essentially a Spiteful redesigned for Royal Navy carrier use, with the addition of an arrester hook, a contra-rotating propeller to eliminate engine torque effects, and power folding outer wing panels.
While it wouldn't serve as a fleet fighter, it would find use as a naval aircraft trainer.