One Piece Chapter 39, page 2: FOR WHOM THE BELL TOLLS

Luffy lets out a thunderous roar that echoes across the entire cliffside (SFX: GOOOO...): "COME OUT, YOU EVIL BUTLER!!!" The sound reverberates down the slope where dozens of defeated pirates lie scattered. Luffy suddenly stops and looks around, sensing a sudden movement. A sharp swooshing sound cuts through the air (SFX: SWOSH! / SFX: HYU...), followed by a sudden, heavy metallic clash (SFX: GAKI-N!!).