The Moulding Mushroom is a type of mushroom that quickly spreads on a ship's rations during the night. The Sea Route of Silence Gang used the mushrooms to infect the Konoha ship sailing toward the Land of Lightning.
At first, it looks like an edible ordinary mushroom, but under the right conditions such as those present in the Sea Route of Silence, it shall release a tremendous amount of spores that grow into toxic mushrooms exponentially. The new mushrooms grow in different colours all over any form of food, tainting it. If one attempts to eat the tainted food a person will develop a purple face, will be covered in mushrooms, and will undergo delusions that compel them to cannibalise others afflicted with the same condition, and if they can't they may resort to consuming non-afflicted living creatures. Some of the mushrooms devour chakra, like in Yamato's case. When people eat them, they become unaware of their own actions, like in the cases of Naruto and Guy. After the mushrooms' effect disappears by getting out from the Sea Route of Silence, those who have eaten the mushrooms will forget what had happened.