The sceptre didn't always belong to the Mouse King. Back when he was advisor to the King of Parthenia, it was left in his care until the heir to the throne, Prince Eric, could prove he was ready to be king. The Mouse used it to turn Eric into a Nutcracker and set about taking over the Land of Sweets. He uses it in his battle with the Nutcracker but it is destroyed when his spell backfires on him.
The sceptre can basically do whatever the Mouse King wants it to; sometimes he chants a spell to go with it, but that isn't always the case. There doesn't seem to be a limit to what it can do; it can shrink objects, light bonfires and create rock giants. The Mouse King frequently uses it to turn anyone who earns his disapproval into "living statuaries", lawn ornaments, paperweights or bookends. It isn't always a sceptre, either; whenever the Mouse King needs it, it can become a sword, a crossbow, or an axe.
|Barbie in the Nutcracker|
Media: Barbie in the Nutcracker
Characters: Clara | King Eric | Mouse King | Pimm | Major Mint | Captain Candy | Peppermint Girl | Gingerbread Boy | Marzipan | Rock Giant | Faeries | Elizabeth Drosselmayer | Owl | Grandfather Drosselmayer | Tommy | Masha | Maid | Barbie Roberts | Kelly Roberts
Locations: Ballet Studio | Barren Valley | Floating Stepping Stones | Forest | Gingerbread Village | Grandfather Drosselmayer's House | Ice Cave | Lush Valley | Palace of Sweets | Parthenia | Sea of Storms | Sugar Plum Island | Treetop Village