Powers: Ate the Gum-Gum Devil Fruit, turning Luffy into a rubber man. This grants him the ability to stretch his body.
Weaknesses: Unable to swim as a result of eating the Devil Fruit.
Bio: Monkey dreamt his whole life of becoming a pirate. That dream was seemingly crushed when he ate a Devil's Fruit as a child. He became a "gummi man" but lost the ability to swim (or ever being able to).
But he showed everyone that said he would never be a pirate when he set off on a journey to find a pirate crew and the greatest treasure of all time.