Mario with Bean Fever.

Bean Fever is a food poison like disease in the Beanbean Kingdom that frequently affects travelers who aren't used to the food in the region. There is only one known antidote to Bean Fever: Crabbie Grass. Once one is infected by the disease, they will become a Bean in three days. Mario was infected by the disease in Mario and Luigi: Superstar Saga, but Luigi found some Crabbie Grass and cured Mario.