We may have assembled not one but two 'Movie Twitterers You Should Follow' features, but there are a couple of big Hollywood names who refuse to express their thoughts in 140 characters or fewer - and Vin Diesel is one such person, posting an astonishing still from Pitch Black threequel Riddick today on Mark Zuckerberg's favourite website. 

For those not in the know about Riddick, it's set - perhaps unsurprisingly - in the aftermath of Chronicles, with everyone's favourite ocularly-enhanced bald badass left for dead on a deserted planet.

To survive, he must call in mercenaries to help him - the very same mercenaries who are out for the bounty on his head. Then there's a lethal storm a-comin', and a man with personal issues with our man Richard B., and suddenly things go from bad to seriously goddamn terrible.

Anyway, here's the picture Mr. Diesel posted to Facebook, accompanied by his description.

"A still from the RIddick set this year. We are in post and I can't tell you how excited I am to see it manifest. You all were such a part of it becoming a reality - willed it into being, so to speak..."

"P.S. Filming Fast this summer is going to be incredible. Thank you again for the opportunity to make magic."

The question is, of course: what on earth is he holding? A make-shift weapon, presumably? Tars Tarkas' skull-onna-stick? If you have any suggestions, let us know in the comment box below.

Riddick has no official release date, but 2013 is a good bet.