Mushrooms

The Super Mushroom is a power-up from the Mario series of video games. It is, traditionally, about the size of "regular" Mario, and has a white stalk below a red and white (originally red and orange) spotted cap. Originally, it was shaped after a common mushroom, but since Super Mario Bros. 2 it gained a more cartoonish shape, with an almost-spheric cap and a stubby stalk.
Shigeru Miyamoto stated in an interview that the Super Mushroom was created by chance. The first sketches of Mario turned out to be too big, for which they were forced to shrink them. Then the development team thought it would be interesting to have Mario grow and shrink by eating a magic mushroom, like Alice In Wonderland. In the story, Alice ate a piece of cake that changed her size. This concept is explored further in, with Poison Mushrooms that shrink Mario into an even smaller size than he usually starts out in, and Mega Mushrooms that turn Mario into a colossal giant.
Because the Mushroom is the most basic power-up, without which other powers can't be granted, it is occasionally used in the Mario series to denote basic rewards or easier skill levels. Winning three consecutive Mushroom cards from the slot-machine goal boxes at the end of each level in Super Mario Bros. 3 will earn the player two extra lives, whereas winning three consecutive Fire Flower cards earns three extra lives, and winning three consecutive Starman cards will earn them five. In Mario Kart games, the first (and easiest) tracks belong to the Mushroom Cup.
Using a Mushroom in Mario Kart gives the player a short boost of speed (and defensive shield for a fraction of a second) in the Mario Kart series of racing games.
In some Mario games, the Super Mushroom heals Mario and friends, such as in Super Mario RPG, Paper Mario, and Mario & Luigi.