Nabbit

Nabbit is an enemy introduced in New Super Mario Bros. U and a playable character in New Super Luigi U. The name "Nabbit" is a play on the words "nab" and "rabbit". Nabbit is a thief who steals items from Toad Houses and runs away with them in his bag. He is a purple rabbit with round eyes, long ears, and black limbs. He also wears a white handkerchief with a drawing of a large mouth with sharpened teeth, similar to Bowser Jr.'s mask, as well as orange shoes and white gloves.

New Super Mario Bros. U
In New Super Mario Bros. U, Nabbit appears throughout several levels. When encountered by Mario and friends, they must chase him throughout the course within 100 seconds. The heroes can also toss Koopa Shells at Nabbit or slide into him to stun him temporarily; or throw fireballs to stop him. When Nabbit is caught, Toad will take the P-Acorn out of the bag and give it to the player as a reward. If players fail to catch him three times, Nabbit will flee and disappear until conditions are met.

Nabbit appears in every world, except Peach's Castle and Superstar Road, and catching him in each of these worlds will add a star to the player's save file. Once he is caught in the necessary worlds, he will still appear in the same levels as before after playing three levels.

The player can first find Nabbit in seven levels:
 * Acorn Plains-1: Acorn Plains Way
 * Layer-Cake Desert-6: Blooming Lakitus
 * Sparkling Waters-4: Urchin Shoals
 * Frosted Glaicer-3: Prickly Goombas!
 * Soda Jungle-1: Jungle of the Giants
 * Rock-Candy Mines-5: Walking Piranha Plants!
 * Meringue Clouds-2: Seesaw Shrooms

He also appears if the player takes too long to open the chest after defeating the enemies in an enemy course, in which case he will steal the item from the chest.

New Super Luigi U
Nabbit reappears in New Super Luigi U, this time as a new playable character (replacing Mario from the original game). Unlike other playable characters, Nabbit cannot use power-ups or ride Yoshis, but he is immune to all enemy attacks, though he can still get knocked back by tougher enemies, such as Grrrols. Also, despite his immunity to enemy attacks, Nabbit can still lose lives by falling into lava, poison water, an abyss, simply getting crushed by certain obstacles, getting eaten by a Cheep Chomp, or running out of time.

The power-ups he collects are released as 1-Up Mushrooms at the end of the level. In single player mode, Luigi must chase him like in the original. Nabbit can also be playable anytime in single player mode by holding on the Gamepad or the Pro Controller or holding the  on the Wii Remote while entering any level, except the Flying Squirrel Ovation level in Superstar Road world where Mii can be played as instead of Nabbit.

Also, Nabbit still comes and steals the item from a chest if the player waits too long to collect a chest despite being on Luigi's side. If the player is playing as Nabbit, the screen fades after taking too long.

Mario Golf: World Tour
Nabbit appears for the first time in the Mario Golf series, as well as his first spin-off and handheld appearance, in Mario Golf: World Tour as a DLC-exclusive bonus character. He is obtained by purchasing the Flower Pack, either individually or via the Season Pass. His normal driving distance is 213 yards, while his star driving distance is 274 yards. His shot trajectory has a huge draw that travels at the lowest height out of all characters.

Mario Party 10
Nabbit is set to appear as a non-playable character in Mario Party 10. Sometimes he appears during Bowser's turn in Bowser Party, giving him two extra Dice Blocks.

Super Smash Bros. for Wii U
Nabbit makes an appearance in Super Smash Bros. for Wii U in the Mushroom Kingdom U stage. It is currently unknown what he does during matches, though it was implied in a Miiverse post by Masahiro Sakurai that he will be able to catch fighters and keep them in his bag, presumably temporarily.

Trivia

 * The character Ravio from The Legend of Zelda: A Link Between Worlds has a similar appearance to Nabbit, as pointed out by several fans commenting on a Miiverse screenshot showing the character. However, Satoru Iwata, during the October 1, 2013 Nintendo Direct, ended up dismissing the similarities as an unintentional coincidence.