Instructions
Play through the "Mad Pitchfork" level until Franky the Pitchfork attacks you. You'll be in a room with several bouncing haystacks and Franky will bounce around and try to stab you.
Jump behind one of the haystacks, making sure that Franky is on the opposite side of it. Jump up and press "A" twice to do a "Helicopter" move that lets you stay airborne for a couple of seconds when Franky does a charge attack. He will smash through the haystack but miss you entirely.
Stand in front of a haystack and press "A" twice when Franky charges to avoid his attack and have him destroy another haystack. Keep either standing in front of or behind haystacks to lure Franky to attack them until all the haystacks have been destroyed. This will end the battle.