Monkey D. Luffy is with a variety of personality traits, including: Childlike; Luffy can be greedy, especially when it comes to food, adventure, or who his crew is. He can also be selfless, sometimes sacrificing himself to protect his friends and family. Optimistic; Luffy is often happy-go-lucky and fun-loving, and he tries to look at the bright side of things. He's also not afraid to laugh at his own misfortune. Ambitious; Luffy has big goals, and his childlike mentality.