Trent from Negative World writes: "Satoru Iwata describes New Super Luigi U’s multiplayer mode as such:
'Since Mario does not appear in the game, players can enjoy multiplayer by playing as Luigi, Blue Toad, Yellow Toad, and Nabbit. Some of you may not know the Nabbit character, so let me refresh your memory.
In New Super Mario Bros. U, Nabbit was a character that stole items from Toad’s house, and players would chase him in different stages. This time around you can actually play as Nabbit.
Nabbit has different abilities from Luigi and the Toads. His speed and jump are the same as the others, but he cannot power up if he collects items. Instead, he won’t take damage when he touches enemies.'
But who is Nabbit?"