The Grumman F9F/F-9 Cougar was an aircraft carrier-based fighter aircraft for the United States Navy. Based on Grumman's earlier F9F Panther, the Cougar replaced the Panther's straight wing with a more modern swept wing. Thrust was also increased significantly. The Navy considered the Cougar an updated version of the Panther, despite having a different official name, and thus Cougars started off from F9F-6 upward.