F1

F1 is the first of twelve 'F' keys located on the top row of a standard QWERTY keyboard; its general purpose is to ring up the help menu of certain programs such as Internet Explorer. In this sense, however, the F1 key is relating to its purpose in M.U.G.E.N, which is (providing the debug keys are enabled) to instantly K.O. a character.

The F1 key was made into a M.U.G.E.N character by Hsiehtm. It is a novelty character that automatically K.O.s a character, like the actual key does if it were pressed during a match. It can knock out almost all characters, but it can't be knocked out itself through normal means; for this reason, it is considered a cheap character. Originally, it was stated that it can't be beaten, which is true to a point, but a few characters including AxAyAzSSS/ADS/Angle Draw Sphere and Ironcommando's A-Bomb, when modified, can knock out F1.