One Piece Chapter 1, page 23-24: Romance Dawn

Luffy is furious and screams at Shanks: "You think it's funny?! He made you look like a weakling!!! Why didn't you fight him?! Sure, they outnumbered you, and maybe they looked pretty tough, but what kind of man lets himself be treated like that then laughs about it? You're a disgrace to all pirates!" Shanks tries to calm him down: "When you grow up maybe you'll understand, kid. He just got some grog on me, that's all. Needless killing doesn't make you a man." Luffy yells: "Hmph! To go find a real role model!" and storms off. Shanks grabs his arm to stop him.

As Luffy walks away, his arm stretches out to an impossible length with a loud "BWOING!". Shanks and the pirates gasp in absolute shock: "His arm's stretching!!! Does this mean... did he-- He couldn't have!" Lucky Roux runs over holding an open chest: "It's not here!! The Gum-Gum Fruit we took from that enemy ship!!!" Shanks grabs Luffy by the collar and shakes him: "Luffy! You didn't eat that fruit, did you!?" Luffy, sweating, replies: "Yeah... I ate it for dessert!! It didn't taste all that great, though...