"As an actor, not showing my chiseled, extraordinary, handsome face was a tremendous sacrifice for me," he joked on Monday before the premiere of the film's trailer at Las Vegas movie-theater convention CinemaCon.
"Paramount, MGM and I made a pact," he added. "We wanted to make a massive global and entertaining movie while doing all we could to never reveal the actual look of Hercules."
Slowly rolling out photos from the set of the film for the past few months via his Twitter page, Johnson aimed to bring fans along on his journey—from his training to his diet and prep.
On Sunday, the 41-year-old actor finally unveiled his "Hercules" look in its entirety.
Via Twitter (http://bit.ly/1rsmwPM), he posted a photo revealing his full beard, shoulder-length brown locks and armor. In the caption accompanying the photo he wrote: "The world's first superhero. (hash)TilDeathOrVictory."
We're offered hints of the Greek hero's abilities in the film's trailer, which debuts wide on Tuesday. In it, Hercules battles the multiheaded Lernaean hydra water monster, the behemoth Erymanthian boar and the massive Nemean lion. In the following clip he classically dons the skinned lion as a headpiece.
But, of course, Hercules is a multifaceted figure, so we're also treated to a brief snapshot of the hero absorbed in a tender lip-lock.
The teaser's conclusion takes us right back to the barbarousness, with the Greek hero fiercely yelling, "I am Hercules!"
At 6 feet 5 inches, the extremely muscular Johnson said he trained harder for "Hercules," which hits theaters July 25, than any other role. "But in the end," he added. "It was all well worth it."
Follow AP Film Writer Jessica Herndon on Twitter at: https://twitter.com/SomeKind