Statue Mario

Statue Mario is a form of Mario or Luigi first appearing in Super Mario Bros. 3. While in this form, the Mario Bros. are invincible to all enemies, though they are immobile.

Super Mario Bros. 3
Although the form itself didn't appear as a power-up, Tanooki Mario had all the powers of Statue Mario in that game. When Tanooki Mario was a statue, he cannot be hurt and if he uses this ability in the air, he can slam down like a Thwomp. This can destroy certain enemies and trigger switches. It will instantly destroy all Goombas and enemies with throwable shells (Koopas, Buzzy Beetles, and Spinies). It can also stomp previously unstompable enemies like Piranha Plants, Piranhacus Giganticus, Venus Fire Traps, Spiny Eggs, Thwomps, Podoboos, Fire Snakes, and Chain Chomps.

The Statue form is also the only way to destroy Roto-Discs and Rocket Engine flames. Statue Mario will sink rapidly underwater and can even oppose the upward currents coming from pipes. This allows him to stomp Lava Lotuses, Bloopers and fish enemies underwater. Boss Bass is the only fish that Statue Mario can't stomp on and the only enemy that can harm him in that form by eating him. In Super Mario All-Stars, Tweester can turn Statue Mario back into Tanooki Mario on contact but he can still turn into Statue Mario while in the Tweester though it will not free him or have any desirable effect. One setback is that while Mario is a statue, he cannot move.

Super Mario 3D Land
In this game Statue Mario/Luigi became a separate form. It can be obtained by using a Statue Leaf. It acts just like Tanooki Mario from Super Mario Bros. 3, the only difference being that Mario and Luigi will get a red or green scarf respectively in addition to the Tanooki suit. In order to turn into a statue, the player has to use the Ground Pound command and it will turn Mario or Luigi into the heavy stone statue that quickly smashes into the ground; in addition, the longer the or  is pressed, the longer the brothers will stay in statue form - it can now be held indefinitely rather than for a limited time. The statue form has many functions, primarily, it will protect the brothers from any hazards in the level, except for lava or the time running out. When Statue Mario mumbles in 2 seconds, they come back to the Tanooki form. It can also take out almost every enemy that cannot be defeated with a normal pound. The statue form also takes away the attention of some enemies and stops them from attacking or following the Mario Bros.

While Tanooki Mario is used often in the regular worlds, the Super Leaf is rarely found in the special worlds. The Statue Leaf on the opposite is found often in the special worlds, but never in the original worlds. That makes Statue Mario the Special World counterpart of Tanooki Mario.

Trivia

 * According to the comic book story "Tanooki Suits Me", Statue Mario's statue transformation is triggered by pressing a button on the front of the suit, and to change back, he has to simply wish he were human again.
 * Statue Luigi and Tanooki Luigi have a honey brown fur, a thin end tail with a single yellow zigzag spot, making him to heavily resemble a fox, or a kitsune.
 * In Super Mario 3D Land, when a statue, Mario holds up his right hand, while Luigi holds up his left.
 * Tanooki Mario is based on the mystical tanooki from the Japanese folklore, who, with the help of special leaves (hence the Super Leaves) could tranform into varius inanimate objects, including statues.
 * Statue Mario's Statue form, in turn, seems to be based on statues of Buddhist priests.
 * In the final levels of New Super Mario Bros. 2, the Koopalings show up and try to turn Mario/Luigi into their statue forms with a blinding light from the Koopa Clown Car. Unlike the other statue forms, this form is involuntary and serves as a hindrance which Mario/Luigi must avoid by hiding behind walls in the background. If they are turned to stone, the player must mash the buttons to revert to normal form.
 * Unlike Super Mario Bros. 3, the Tanooki and Statue form in Super Mario 3D Land are separate items.
 * The effect of the Stone Cap in Paper Mario is similar to Statue Mario, as it transforms Mario into stone statue that invincible to any damage yet are unable to move.