Invincibility Leaf

The Invincibility Leaf is a power-up that appears in Super Mario 3D Land and New Super Mario Bros. 2, both for the Nintendo 3DS. In Super Mario 3D Land, it only appears after Mario loses five lives in a level that is not already completed. It will not appear when re-visiting a completed level or a Special World level. This means Luigi cannot obtain it unless the player skipped any levels in the normal worlds (for example, by using a Warp Zone). Touching it will give Mario a shining white and golden Tanooki Suit, making him White Tanooki Mario, and it will make him invincible, as the Star also does, but the invincibility lasts for the entire level.

It may have the same effect in New Super Mario Bros. 2, but it's yet to be announced how many lives Mario has to lose before getting the item. Also, it turns Mario into White Raccoon Mario instead of White Tanooki Mario.