Body Mushroom

Body Mushroom (カラダカラキノコガハエルダケ, Karada kara kinoko ga haeru dake) is the type of mushroom that grows on Amazon Lily. If a person eats these mushrooms, many mushrooms will start growing on their body which can be fatal. To cure that, one has to pull the mushrooms out of the person and the person has to be burned to destroy the roots. Luffy ate one thinking it was a Wairidrake, but then he was covered in mushrooms so the Kujas has to pull them out and burn him.

Trivia

 * The medical treatment of "burning" the mushroom to get it off is indeed a natural cure for several biological dieases that grow on the skin. However this is normally done with acids rather then fire as the Kuja used; though in some cultures burning the skin with fire was indeed used as a cure for some dieases.