A spriteswap (not to be confused with sprite edit) is a M.U.G.E.N character that has another character's exact coding, except with different sprites. A spriteswap of a character will contain the exact same moves, normally pulled off the exact same way, with the exact same effects as well. In a lot of spriteswaps, you can even see the sprites of the original M.U.G.E.N character in some of its animations.