Once Upon a Time will go on an extended hiatus on December 15.

But not before revealing a new villain to the television universe.

E! News confirms that Rebecca Mader (Lost, No Ordinary Family, Work It) has landed a major role on the ABC drama, coming on board as a deliciously evil character whose identity will be revealed in a promo following the 2013 finale.

But let the guessing games begin now, OUAT Fanatics!

ABC also announced that Alexandra Metz will portray Rapunzel and debut some time this spring.

Once Upon a Time Season 3 bids farewell on December 15 and does not return until March 9.

Matt Richenthal is the Editor in Chief of TV Fanatic. Follow him on Twitter and on Google+.