From the Super Mario Wiki
A Super Leaf is one of the many power-up items in the Mario series. Super Leaves originated in the game Super Mario Bros. 3, where they turn Mario into Raccoon Mario. As such, Mario or Luigi will grow raccoon ears and a raccoon tail. This tail has many functions. Mario or Luigi can descend slowly by wagging the tail; he can briefly fly instead if he fills the Power Meter (by running) beforehand. Mario or Luigi can also tail whip to hit Blocks and enemies.
Super Mario series
Super Mario Bros. 3
Super Leaves first appear in the game Super Mario Bros. 3. The item transforms Mario or Luigi into Raccoon Mario or Raccoon Luigi, respectively. If they run for long enough, the Power Meter becomes full. When this happens, they can jump and fly by tapping . They can also float down slowly by tapping . If they hit , they will swing their tails, which can hit ? Blocks and enemies.
Super Mario World
Super Mario 3D Land
After a long absence, Super Leaves reappear in Super Mario 3D Land; however, they turn Mario into Tanooki Mario; Luigi's Tanooki form is now kitsune-themed and called Kitsune Luigi. In spite of the change, the Tanooki forms granted by Super Leaves still act as Raccoon Mario, but without flight. Gliding is executed by holding or , rather than tapping the buttons. The tail whip is still done by pressing or . Additionally, the leaves in this game were redesigned by being given stripes, eyes and a "bite" mark. There is also a gold and white variation of the Super Leaf in the game called the Invincibility Leaf, which gives Mario a glowing, white Tanooki costume, and makes him invincible. Mario can only obtain this power-up if the player has lost five lives in a (skipped) normal world level. Another item similar to the Super Leaf is the Statue Leaf, which allows Mario to turn into Statue Mario for a brief time (essentially functioning as the original Tanooki Suit did, except there is still no flight and the transformation, done through a Ground Pound, lasts much longer).
The Super Leaves are also tied into the game's plot, rather than being just mere power-ups. It is revealed in the game's opening that the Mushroom Kingdom's Super Leaves grow from a rare tree called the Tail Tree (on account of its oddly-shaped bough). During a storm, Bowser stole all of the tree's mythical leaves by blowing them off the tree, using them to power-up his minions, giving them "Raccoon" forms and bestowing them with tails to attack and float around; some of them even become Bowser Impostors this way.
New Super Mario Bros. 2
Super Leaves also appear in New Super Mario Bros. 2, having the same design from Super Mario 3D Land and Mario Kart 7. Unlike in Super Mario 3D Land, they retain their original form and abilities from Super Mario Bros. 3. However, like in Super Mario 3D Land, Luigi's Raccoon form is kitsune-themed and called Fox Luigi. While in this form, the Power Meter appears in the bottom left corner of the top screen; if Mario runs for long enough to fill it up, he can fly by holding or . He can also glide down by holding or . He can swing his tail with or to activate ? Blocks and defeat enemies. In addition, if Mario loses five lives in a level, a block with an Invincibility Leaf inside appears, just like in Super Mario 3D Land. The only difference is that it changes Mario or Luigi into White Raccoon Mario or White Fox Luigi, respectively. In this form, Mario is invincible, he can run on water, and the Power Meter fills up much faster. He can still, however, lose a life by falling into lava, bottemless pits, Poisoned Water, touching a Boohemoth, by being squished between two walls.
Super Mario 3D World
Super Leaves make a return in Super Mario 3D World, albeit significantly less common than in its predecessor. They are used as they were in Super Mario 3D Land, still granting that game's basic Tanooki Suit, or in Luigi's case, Kitsune Suit. Tanooki Mario's ears and belly are lighter-colored, Peach and Rosalina have darker-colored suits with puffy shorts with darker legs (Tanooki Rosalina also has darker arms and shorter gloves.), and Toad does not have a scarf, unlike in Super Mario 3D Land. Tanooki Peach retains her floating ability, and can use the form's glide after afterwards.
Super Mario Maker
The Super Leaf is set to appear in Super Mario Maker, where it is exclusive to the Super Mario Bros. 3 style, retaining its properties from that game.
A Super Leaf appears in volume 4 of Super Mario-Kun, although the arc deals primarily with Super Mario World. Luigi, who is apparently controlled by Boos, traps Mario and Yoshi with a rope. Mario hits a ? Block, and he grabs the Super Leaf that appears and transforms into Raccoon Mario. He then frees Yoshi and himself and knocks the Boos from Luigi, returning Luigi to normal.
Mario Kart series
Mario Kart 7
Super Leaves appear as an actual item in Mario Kart 7. Here, they create a tanooki tail on the back of the kart which doubles as an offensive and defensive feature. Pressing or swings the tail which can hit other karts and protect the player's kart from other items such as Green Shells. However, if the tail is hit by shells while idle, it will disappear. When activated, the Super Leaf lasts for 10 seconds, or until the player spins out, tumbles over, or is hit by a Spiny Shell.
The tail replaces the kart's propeller when used underwater, and it lengthens air glides.
Mario & Sonic at the Sochi 2014 Olympics Winter Games
A single Super Leaf appears in the Mario version of the Dream Event, Figure Skating Spectacular, in Mario & Sonic at the Sochi 2014 Olympic Winter Games. It appears after defeating the Bowser Impostor, similar to Super Mario 3D Land.
Super Smash Bros. for Nintendo 3DS / Wii U
The Super Leaf appears as an item in Super Smash Bros. for Nintendo 3DS / Wii U. It transforms fighters into the Raccoon form and allows them to float in the air by holding the jump button.
Super Smash Bros. for Nintendo 3DS / Wii U Trophy information
Names in other languages