Doctor Who's upcoming Christmas special could be a little too scary for youngsters.

The BBC series embraced a darker tone for season 8, and this heightened sense of danger may carry into the season's typically family friendly episode. Titled "The Last Christmas," the holiday episode may have some viewers taking refuge behind the sofa.

"This is a scary episode with scary monsters and some proper horror tropes going on," said showrunner Steven Moffat, according to Zap2It. "I keep saying it's like 'Alien' crossed with 'Miracle on 34th Street,' and that's a very strange mashup."

However, Moffat doesn't believe hiding behind the couch is a bad thing, nor something that will give children nightmares.

"Doctor Who is scary in the way a rollercoaster is scary. It's not scary like being trapped outside your house at night. It is fun scary," Moffat assured Doctor Who TV. "The thing people never say about hiding behind the sofa, is that hiding behind the sofa is itself fun. It is a fun thing to do. Kids like being scared of Doctor Who. It doesn't horrify them. It doesn't petrify them. It is just an enjoyable thrill. There is nothing wrong with a bit of adrenaline."

Determine where "The Last Christmas" falls on the scare-o-meter for yourself when "The Last Christmas" airs Dec. 25 on the BBC and BBC America. Click the video below to see a preview.

Tags: Doctor Who television BBC BBC America