Poison Mushrooms are items that are really poisonous (hence the name), and will make Mario small or die. They have different appearances. Some look really like they are poisonous (with different colors), but they sometimes look like Super Mushrooms, thus being a trap. Similar items are 1-Down Mushrooms, that does the reverse of a 1-Up Mushroom. In Super Mario Universe: Darkness Adventure it is used to make him Poison Mario. New Super Mario Bros. D.I.Y. New Super Mario Bros. Omega New Super Mario