Though it's not quite December yet, the countdown is on for the Doctor Who Christmas Special, The Snowmen.  The most important element of this new special will be the introduction of Jenna-Louise Coleman as Matt Smith's new companion.  The special was written by executive producer Steven Moffat (also of the BBC's Sherlock series), and will tackle some very serious emotions for the poor Doctor.  Hit the jump for more on what to expect from The Snowmen, along with the trailer, poster and still images.  The special airs Tuesday, December 25 at 9 p.m. ET on BBC America.

Doctor Who: The Snowmen marks Jenna-Louise Coleman's second appearance in the series - she also had a role in the season premiere "Asylum of the Daleks" as Oswin, who died at the end of that the episode.  That raises a lot of questions that may or may not be addressed in the Christmas Special as to whether or not her companion character Clara is Oswin, or another person entirely, or whether she's traveling in an opposite direction in time as the Doctor (which has already been done with River Song).

Both Smith and Coleman have hinted that it's more likely that Clara is just a new character, but even though the two had chemistry in her brief turn early in the season, it will be interesting to see how that plays out now, especially with the Doctor in deep mourning.

If you crave even more Who before Christmas, check out the Doctor Who Tumblr, which reblogs a great deal  of in-depth fan analysis of the pictures, trailer and more. As for the special itself, I'm particularly looking forward to the cameo by Richard E. Grant (Withnail & I) as the evil mastermind mind behind the army of viscious snowmen …

Images via Zap2It.