Werewolf hunk Taylor Lautner shows off his beefed-up physique on the December cover of Men's Health and ET's got a behind-the-scenes peek at his photo shoot for the mag.

Taylor packed on 30 pounds of muscle in a year to convincingly depict Jacob Black's transformation into an almighty werewolf in 'The Twilight Saga: New Moon,' which arrives Nov. 20.

And the star says he plans on bulking up even more for the third 'Twilight' film, 'Eclipse,' expected out June 30, 2010. "My character continues to grow," he tells Men's Health, "so I'd like to pack on at least a few more lean pounds."

To maximize his muscle gains, Taylor varies the amounts of weight he lifts and the number of repetitions he performs, his trainer tells the mag.

Catch Taylor on the cover of the new issue of Men's Health, on stands Nov. 17.