One Piece Chapter 17, page 19: Chapter 17: HIGH LEVEL, LOW LEVEL

Luffy declares with absolute certainty, "I'M GONNA BE KING OF THE PIRATES." Buggy is momentarily stunned, then bursts into mocking laughter, shouting, "DON'T BE A FOOL! IF YOU'RE KING OF PIRATES, THEN WHAT AM I!? GOD OF THE PIRATES!? THE WORLD'S TREASURE WILL BE MINE! SO FORGET IT!"