Stars to voice animated adventure.

DreamWorks Animation has announced that ‘The Big Bang Theory’ star Jim Parsons and singer-turned-actress Rihanna (‘Battleship’) are to lend their voices to ‘Happy Smekday!,’ a feature film based on the critically acclaimed book ‘TheTrue Meaning of Smekday’ by Adam Rex.

Tim Johnson (‘Over the Hedge,’ ‘Antz’) will serve as the film’s director working from a screenplay by Tom J. Astle and Matt Ember (‘Get Smart’).

In ‘Happy Smekday!’ an alien race invades Earth and uses it as a hideout from their mortal enemy. When one lowly alien accidentally notifies the enemies of his whereabouts, he is forced to go on the run with a teenage girl. The two become unlikely buddies and embark on a comical globe-trotting adventure to right his wrongs, in which our alien hero learns what it really means to be human.

“When I read Adam Rex’s remarkable book, I knew it would make an amazing film. I can’t wait to introduce audiences to theunique world and characters of ‘Happy Smekday!’” said Johnson.

Chris Jenkins (‘Rio,’ ‘Surf’s Up’) and Suzanne Buirgy (‘KungFu Panda 2’) are producing with DreamWorks Animation’s Head of Development Gregg Taylor overseeing the project.