That lapin committed larceny!
http://www.nintendoworldreport.com/news/32303
New Super Mario Bros. U will have a new feature that tasks players to capture a burglarizing bunny before he makes off with Toad's stash.
When exploring the game's world map, a character named Nabbit will appear within one of the available courses. Enter that stage, and you'll witness the Nabbit make off with a bag belonging to Toad. As the clock winds down, players need to catch up with the purple pack-pincher. Apprehend the fiend and you're able to hand over the belongings to their proper owner. In return, Toad will bestow you with a P-Acorn, a single use item that allows for unlimited flight in any course.
Video of the event revealing Nabbit can be found here (IGN).
Also announced is a Coin Battle mode supporting five players. Players can modify the coin layout in special Coin Battle levels using the Wii U GamePad and then four players can compete in collecting the most coins. During the competition, one player can place Boost Blocks using the GamePad to assist the other players.
New Super Mario Bros. U will release alongside the Wii U on November 18.