The worst Christmas-themed film (and possibly film in general, full stop) is 'The Christmas Martian', which I'd be surprised if anyone on this board will ever have seen, luckily for them. It's impossible to describe - try imagining something filmed in the manner of The Magic Roundabout, only live-action, with barely any dialogue and seemingly edited by someone who's overdosed on their Fluoxetine. Not to mention the fact that the 'Martian' whom the two child protagonists befriend bears more than a passing resemblance to Jonathan King. Such an indescribably godawful thing could only have been conceived in the hazily lost mists of the 70s, and even more fortunately the days when ITV thought nothing of trotting out such obscure no-budget crap are as equally evanescent.