'Smurfs 2' trailer: Katy Perry turns naughty Smurfette

Sony Pictures Animation has put out a new trailer for "The Smurfs 2," which stars Neil Patrick Harris, Christina Ricci, and Sofia Vergara. In the sequel to 2011's "The Smurfs," Gargamel creates the miniature Smurf wannabes, "The Naughties" to infiltrate the land of the blue creatures and turn Smurfette -- Katy Perry reprises her role -- against her own kind.

The Smurfs enlist the help of their human friends to save Smurfette from her own naughtiness, because only she holds the key to converting the Naughties into full-fledged Smurfs.

"The Smurfs 2" hits theaters July 31, 2013.