I've heard far too often the statement that the knight differs from other pieces because it can fork, when in truth every piece can fork. An example of a king fork appears in the correct line of play from this position from the endings section of Chess Informant 23.
Black to move
Black played 1...Ke6, and the game continued 2.Kb5 Kd5 3.Kb6 Nb8 4.Nf6 Kd6 5.c7 1-0.
Black missed an easy draw.