Between the first and second installments of The Twilight Saga, Taylor Lautner was told they might recast the role of Jacob with someone more buff... so Lautner promptly went off and gained a whopping 30 pounds in muscle. That's the weight of a small child or a fully-grown Cocker spaniel.
Anyway, as we all know, Lautner kept the role of Jacob and stole the hearts of teenage girls around the world from his distinctly weedier co-star Robert Pattinson.
High-minded Hercules or Brainless Beefcake?
At the moment he's definitely more muscle than mind, but he's just a young'n so there's still time.