Merfle Barrel

Merfle Barrels are barrel-shaped cages used by the Shake King to imprison the Merfles in Wario Land: Shake It! In each regular level, Wario must find the Merfle Barrel, pick it up, and frantically shake it to free the Merfle, initiating a timer that prompts Wario to hurry back to the start of the stage. Wario can neither throw the Merfle Barrel nor walk while holding it.

Most of the time, Merfle Barrels are located at the end of a level. Alternatively, some levels like Launchpad Labyrinth and Lowdown Depths have the Merfle Barrels located roughly at the beginning of the level instead, with an obstacle preventing Wario from heading back to the starting point once the Merfle is freed, prompting him to navigate through the entire level on a time limit to get back. In some levels, there are blue, metallic blocks that will break once Wario destroys a Merfle Barrel, granting access further into the area.

In Subwarine levels, Merfle Barrels are smaller, and the Merfle inside one breaks out by itself once the gate at the end of the level is destroyed.