Dwayne 'The Rock' Johnson unveils completed bull skull tattoo

Dwayne 'The Rock' Johnson has unveiled a new skull tattoo on his right arm.

The professional wrestler-turned-actor is no stranger to body art, and has a number of Polynesian-style inkings on his left shoulder, in honor of his mother's Samoan heritage.

Johnson also had a tattoo of a bull on his upper right arm, a reference to his old nickname The Brahma Bull, but has since had tattoo artist Nikko Hurtado update the motif with a much more intricate design featuring a bull's skull.

"After approximately 30 hours of tattooing (4 sessions) with my good bud and iconic artist @nikkohurtado, the story of my skull is complete," the 45-year-old star captioned a short video of the inking posted on his Instagram page on Monday (27Nov17).

Johnson then went on to explain that the bull horns represented "forward progress" and his desire to "dig deep" and work hard. While the eye at the center of the design is the "mana" or type of spiritual force and power that he draws upon.

"It's everything. It's where I draw my strength from all things I love and protect," he explained. "As with my Polynesian tattoo on the left side of body, the symbolic mana lays over my heart. We all have mana. Our strength. You just have to find it."

Johnson began the process of getting a new tattoo in August after spending a long time discussing the concept with Hurtado. The artist has worked with stars such as Drake, Kat Von D and Fred Durst.

"All my ink is a rite of passage and spiritual and the MANA (power and spirit) has to be right before we begin," Johnson shared previously. "Mana is strong with world renowned Nikko. We talked for hours about the man I am today, compared to who I once was. And who I'll always be. We all desire to grow and evolve."