Cat Mario

Cat Mario or the Cat Bell is a new power-up found in Super Mario 3D World. It can be used by all the playable characters in the game: Mario, Luigi, Princess Peach, Toad, Rosalina, and even Bowser (in the final boss). Cat Peach appears as a Mario Kart 8 DLC character.

Uses
The main use of the Cat power-up is the ability to climb up walls and even the Goal Pole at the end of the level. It can also pounce on enemies, slide into them, and scratch them, making it the only actual melee attack in the game.

The new Cat Wheels appears in the game and if scratched, can raise platforms. These platforms often allow the player to collect Green Stars, coins, or other collectibles. The Lucky Bell power-up allows the character to become Lucky Cat Mario (Luigi, Peach, etc.). This item can let the player turn into a golden statue similar to the Tanooki Statue from Super Mario 3D Land.

Other
Like the Tanooki Leaf item, this power-up can be used by several enemies in the game specifically Cat Goombas and Cat Bullet Bills.

The final boss of the game, Meowser, is Bowser under the influence of a Cat Bell. This allows him to climb up walls and with the help of the other new item in the game, the Double Cherry, Meowser can clone himself.