Poison Mushroom

A Poison Mushroom (or Poison Shroom) is a Mushroom that powers down or defeats Mario or Luigi if they touch it. They have the opposite effects a Super Mushroom may have. They first appeared in the Japan-only game, Super Mario Bros.: The Lost Levels. Currently, they appear now and then, hindering the player.

''Super Mario Bros.: The Lost Levels
In Super Mario Bros.: The Lost Levels, a Poison Mushroom will kill Small Mario or Luigi, or revert Super or Fire forms into small; they have no effect on the Invincible form or the small form that is still flickering from a recent injury. Another way of getting rid of one is to reveal another mushroom, such as a Super Mushroom or a 1-Up Mushroom, as this causes the first mushroom to disappear. Poison Mushrooms are found in Brick Blocks and ? Blocks, coming in many different colors in the original FDS game. In the remake of Super Mario Bros.: The Lost Levels, Poison Mushrooms changed their main appearance to blue.

''Super Mario 3D Land
Poison Mushrooms return in the Mario platformer games, after 25 years of absence (not counting spin-offs), by appearing in the Nintendo 3DS game, Super Mario 3D Land. In this game, they somewhat behave like enemies as they follow Mario or Luigi around until he is in an area that the Poison Mushroom is unable to get him, or falls into a bottomless pit. The player is also able to destroy them by launching a fireball or boomerang at them, or transforming into a statue to make them vanish on contact. Their appearance is that of a purple mushroom with pink spots that emit a purple dust (possibly spores) when released and grabbed. They appear only in the Special Worlds, and their effects are the same as in Super Mario Bros.: The Lost Levels, where Mario or Luigi can lose a life if they grab one in their small form.

''Donkey Kong
Poison Mushrooms were featured in the Game Boy version of Donkey Kong. Sometimes, Donkey Kong or Donkey Kong Jr. would throw them at Mario, and sometimes they were contained inside barrels. Whenever Mario comes in contact with one of them, it will cause him to briefly shrink in size, disabling some of his abilities in the process (the ability to swim, climb ladders, etc.). After a few seconds, Mario grows back to his regular size.

''Super Mario Kart
Poison Mushrooms were also featured in Super Mario Kart as items, however they were only used by the CPU-controlled drivers Toad and the Princess, and not usable by the player. If a player drove into a Poison Mushroom, they would become small, ending up moving slow and vulnerable to other karts in the area, as they could end up squashed if run over by a full-sized kart. An interesting feature of the Poison Mushroom in Super Mario Kart is the fact the player can also become big again if they run into another Poison Mushroom; this also works if the player were made small from a Thunderbolt by the other player (as CPU players cannot use a Thunderbolt in this game).

Mario Kart Arcade series
In both Mario Kart Arcade GP and its sequel Mario Kart Arcade GP 2, the Poison Mushroom returns as one of Toad's special character items. Like in Super Mario Kart, Toad can use the mushroom to his advantage by causing his opponents to shrink if they come in contact with his poison mushrooms. However, unlike in Super Mario Kart, Toad can now throw the Poison Mushrooms either in front of him as well as behind him (providing him with advantages in both ways).

''Mario Party
In Mario Party, when landing on a Mushroom Space, if the player chooses the Poison Mushroom, he or she loses his or her next turn. In this game, it was referred to as a "Poisonous Mushroom", unlike other games.

''Mario Party 3
In Mario Party 3, the Poison Mushroom is an item that the players can use on either themselves or one of their opponents. A player who is cursed by a Poison Mushroom can only roll the numbers 1-3 on their next turn. It is possible to eliminate the curse by using another Mushroom or a Magic Lamp. It is Waluigi's favorite item.

''Mario Party 5
In Mario Party 5, the Poison Mushroom could be found as a capsule. If a character lands on a space where it has been placed or if the player uses it on his/herself, they can only roll the die with numbers from 1 to 5.

''Luigi's Mansion
In Luigi's Mansion there are Poison Mushrooms that bosses throw when Luigi tries to suck them up. They make Luigi small and lose pearls and coins, also making them escape as Luigi is too tiny to suck up anything bigger than a lost pearl. Also, if Luigi calls for Mario by pressing the button, his voice is high in pitch.

''Mario & Luigi: Superstar Saga
In Mario & Luigi: Superstar Saga, one of the things Trunkle can suck in his mouth during the "Envelop and Heal" move is a Poison Shroom. They are colored the same, and Poison a brother if touched. Popple sometimes throws them during his "Throw from the Bag" move; these Poison Shrooms cause more severe damage when touched. When the brothers travel to Little Fungitown, Mario eats an Invincishroom, a mix of a Starman and a 1-Up Mushroom. However, Mario, being an outsider, was not immune to the dubious concoction and fell gravely ill. This Invincishroom was, to Mario, like a Poison Mushroom.

''Mario & Luigi: Partners in Time
In Mario & Luigi: Partners in Time, a Poison Shroom can be an item used by the two Dr. Shroobs and also Swiggler in the battle against him. The Shroobs also resemble poison mushrooms.

''Super Smash Bros. Melee
Darker red Poison Mushrooms, with sinister eyes were later seen in Super Smash Bros. Melee, in which it temporarily shrinks characters down to one-fourth their original size. That makes the player smaller, but also makes him/her easier to KO.

''Super Smash Bros. Brawl
In Super Smash Bros. Brawl, Poison Mushrooms had another side effect. Not only does the fighter become smaller and lighter, but his/her attack power drops greatly as well. An attack with strong knockback would pack less power than normal when the fighter is tiny. They appear in the Subspace Emissary in some stages.

''Mario Hoops 3-on-3
In Mario Hoops 3-on-3, Poison Mushrooms appear in Power-up panels. They make the player weak and slower.

''Super Mario RPG: Legend of the Seven Stars
The bad Mushroom, only found in Seaside Town, does not recover HP and is used only in battle. When used, they poison an enemy of choice, but some enemies don't get poisoned, so it is not that useful. They have the same appearance as a regular Mushroom in the game.

''Paper Mario: The Thousand-Year Door
The mushroom was seen once again in Paper Mario: The Thousand-Year Door. Poison Shrooms could be created by Zess T. by mixing a Slow Shroom and Inky Sauce / Point Swap or Trial Stew and a Dried Bouquet. If Mario or his partner eats this mushroom, the user will lose half his HP and be afflicted with the Poison status. Strangely, in battle, there is a small chance that when eaten, the Poison Shroom won't poison its user, but will restore all HP instead. There is a common misconception that the Feeling Fine badge(s) are required for this to happen, but it is simply a random occurrence. They're one of the pictures that the player can earn when in battle. If three in a row appear, Mario's HP, FP and SP will all be cut in half and all of the audience members will leave.

Ghost T. also died because he ate a Poison Shroom on the Excess Express.

''Super Paper Mario
In Super Paper Mario, Poison Shrooms are a much more common occurrence than in its predecessor, occasionally being dropped by Zombie Shrooms, Cursyas, and their relatives. They are used slightly more in recipes; for example, a single Poison Shroom can produce a Dangerous Delight. In addition, any recipe that requires a Poison Shroom can be cooked using a Ghost Shroom instead, if Poison Shrooms are in short supply (Ghost Shrooms can be bought from various shops, or obtained via Merlee's charms).

Trivia

 * Although the Poison Mushroom is considered as a Power-up sometimes and acts like one as the Super Mushroom, it is not a Power-up as it has an opposite effect to other Power-ups. Rather, it is considered a Power-down, trap item, or hindrance.
 * The Poison Shrooms on the Paper Mario: The Thousand-Year Door's slots have faces, but the Poison Shroom item doesn't.
 * It was erroneously stated in Super Smash Bros. Melee that Poison Mushrooms first appeared in Super Mario All-Stars, when in actuality they first appeared in Super Mario Bros. 2 (Japanese Version). This was corrected in Super Smash Bros. Brawl.
 * The reason for this may likely be due to the fact that Super Mario Bros. 2 (Japan) was never released for the NES. However, despite this fact, several characters from Japan-only titles appeared as trophies in the North American version of the game.