Benedict Cumberbatch might look like an otter, but he looks even more like a dragon, at least where "The Hobbit" trilogy is concerned.

A new behind-the-scenes video from "The Hobbit: The Desolation of Smaug" has arrived online, showing what exactly Cumberbatch went through in order to become the menacing dragon mentioned in the title. He appears only toward the end of "Desolation of Smaug," but the scenes between Bilbo Baggins and the slumbering, snarling, scaly sky-serpent are among the most memorable not just in the film, but in all the Middle-Earth movies.

Watch Cumberbatch writhe and wiggle on the ground, contorting his face and saturating his voice in oozing, dripping menace, in the video below:

Cumberbatch returns as the deadly Smaug in "The Hobbit: The Battle of the Five Armies," hitting theaters on December 17.