One Piece Chapter 18, page 20: Buggy, 'The Clown Pirate'

Buggy steps on the stabbed straw hat, laughing hysterically, 'KUHAHAHAHAHAHAHA WHAT SORT OF TREASURE IS THIS RAG-LIKE-HAT?!' Luffy grinds his teeth in pure rage, his face shadowed. Flashback panels show Shanks smiling and saying, 'THIS IS MY FAVORITE HAT, YOU KNOW. WHEN YOU BECOME A GREAT PIRATE IN THE FUTURE, YOU'LL RETURN THAT HAT TO ME.' Back in the present, Luffy charges forward with a furious roar, 'THAT'S THE HAT I SWORE MYSELF TO WITH SHANKS!!!'