From the Super Mario Wiki
A Dried Shroom is an item in the Paper Mario series. An item known by the same name in Japan, yet called a Wilt Shroom in the English translation, appears in Super Mario RPG: Legend of the Seven Stars, the precursor to the Paper Mario series.
In Paper Mario, Dried Shrooms are only sold in Dry Dry Outpost and by Rip Cheato. Although they heal only 1 HP, Dried Shrooms are required to be bought to visit Moustafa. However, the player must buy a Dried Shroom and then a Dusty Hammer at Dry Dry Outpost in that exact order, or it will not trigger the chain of events that allows the player to see Moustafa. Black Li'l Oinks leave them behind as well. When Mario eats a Dried Shroom in battle, he gags and sticks his tongue out in disgust; this is the only item he does this with.
In Paper Mario: The Thousand-Year Door, Dried Shrooms are sold at Westside Goods in Rogueport for two Coins. Any mushroom becomes a Dried Shroom when cooked with a Mr. Softener. Mario has to buy a Dried Shroom and a Dizzy Dial to gain access to Don Pianta. Also, Dried Shrooms sell for one coin everywhere except for Twilight Town, where they sell for four coins. The Puni Petuni is seen holding a Dried Shroom while waiting to be rescued from imprisonment by the X-Nauts, revealing to the other Puni's it was originally a regular Mushroom she had picked earlier to give to her brother Punio but it had dried out regressed to a Dried Shroom. After Punio and Mario rescues her and the other Puni from their cell, Petuni gives Punio the Dried Shroom, who eats and lies saying it tastes fine to cheer up Petuni.
Once the Cookbook has been given to Zess T., Dried Shrooms can be cooked to make Shroom Fries. These can then be sold at the neighbouring shop for 5 coins. Since it only costs 2 coins to buy a Dried Shroom, it is an easy way to gain money and Shop Points.
After Mario defeats the Shadow Queen in Paper Mario: The Thousand-Year Door, a mysterious treasure chest is found by Professor Frankly. If Mario chooses to come back to Rogueport after beating the game, the professor will find that it contained a measly Dried Shroom, which he, however, views as a precious scientific relic as it proved that ancient societies ate mushrooms.
In Super Paper Mario, Dried Shrooms are dropped by Putrid Piranhas, Poison Cherbils and Poison Pokeys and other enemies that cause poison. In that game it heals 1 HP and cures poison.
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