One Piece Chapter 18, page 12: Buggy, 'The Clown Pirate'

Luffy swings his leg to strike Buggy, shouting, 'SCYTHE!!' However, Buggy anticipates the move and shouts, 'BARA BARA EMERGENCY ESCAPE!!' He splits his torso and legs apart with a 'POP!!' sound effect, allowing Luffy's leg to swing harmlessly through the empty space between his separated body parts.