Dwayne Johnson's Maui wig weighed "seven pounds more with all the water" during the gruelling Moana shoot.
The 53-year-old actor - who voiced the shapeshifter Demigod in the original 2016 animated classic and its 2024 sequel - is reprising his role in the new live action remake, and his "two and a half hour" transformation into the beloved character was a long process.
Director Thomas Kail told Entertainment Weekly: "We knew that it had to be something that could have real lift to it.
"Because you're doing this on the water, 'what does it look like wet?' is a real conversation when you're making Moana.
"That one weighs seven pounds more with all the water in it for all those hours a day."
There was also the issue of prosthetics and his bodysuit, which Johnson - who first rose to fame as The Rock in WWE - admitted he "didn't anticipate".
He said: "The thing that became a challenge, that I had to work through very quickly, that I didn't anticipate was the prosthetics and the hair and then the body. That is an additional 40 pounds on you.
"There's a freedom when you perform, whether it's as an actor or singing.
"So that was an adjustment on how to actually work my emotions through the 40 pounds of prosthetics and hair and body that I had on me."
Meanwhile, Johnson noted that it wasn't possible for him to "lose the weight" because typically it goes from the neck, and it would've looked silly with the bodysuit.
He explained: "I couldn't have a big bodysuit and then a small little skinny neck. Forty, 50 pounds is a lot to put on.
"Then it's a lot to maintain for months... It was gruelling because of the suit and how hot it was.
"Wait till you see pictures. In between takes, there's literally five, six people, all [with] fans, opening me up, pulling my hair back."
There was a moment where the production team thought about recreating Maui's iconic look with "visual effects, body and everything", but instead they put makeup designer Joel Harlow to work.
Johnson added: "There's also a tactile, emotional resonance when it's a real bodysuit. It moves and breathes with you.
"So we thought the best iteration of this was, let's go for it, let's challenge Joel, and he rose to the occasion."
