Mega Mushroom
The Mega Mushroom is a rare variety of mushroom found in the Mushroom Kingdom. When eaten, they grow their consumer to a massive size. They first appeared in Mario Party 4, with a light green cap. It could be obtained by landing on a Mushroom Space, purchasing it from an item shop, getting it from an Item Bag, or winning a mini-game on the board. They let the player roll two Dice Blocks at once, making the player grow huge and crush other players as they stomped across the board, stealing 10 coins from them. Additionally, a Super Mega Mushroom was available, colored entirely translucent green. The Super Mega Mushroom did the same thing but with three Dice Blocks.
They recently reappeared in New Super Mario Bros., where they yet again made Mario grow to a humongous size. In this colossal form, Mario could stomp across the level and crush anything in his path - enemies, blocks, Warp Pipes, and even the flagpole at the end of the level. These mushrooms were rarely found, and almost always came from Toad Houses or Red Flying Blocks. Besides the Toad Houses, they only appear in two levels (without exploring and finding secret areas within the level), 1-1 and 7-5. The player is not 100% invicible in this form, however; if the player was to jump and land on a hole covered with bricks, the player would fall through, thus, losing a life, if the hole is big enough. Additionally, if Mario or Luigi were to do a Ground Pound after eating a Mega Mushroom, a group of Goombas or Coins (or both) would fall from the sky.
In Mario Kart Wii, the Mega Mushroom is an item obtained from the Item Box. When a player uses this item, they become bigger, able to crush other players for a certain amount of time, reducing their speed. While the item is active, the player is immune to all items except for the Star, Bullet Bill, Blooper and Thunderbolt. Should a player get hit by a Thunderbolt while he or she big, he or she will shrink back down to their normal size rather than become tiny. The Mega Mushroom's theme music from New Super Mario Bros. is played for the duration of the item's effect.