After 60 years of crushing, fighting and roaring, Godzilla shows no signs of stopping. The oversize lizard that has attracted generations of fans returns Friday in a film that harks back to the creature’s roots. The filmmakers behind the latest iteration mainly used the 1954 original, from Toho Studios, as a template for fleshing out the monster’s looks and the movie’s narrative.

Gareth Edwards, who directed the new version, told his designers to imagine Godzilla as an animal that had really existed and that, 60 years ago, some people saw rise from the sea off Japan. They didn’t have a camera, so they described the creature, and Toho made its films based on those accounts. “In our film, people are going to see the original animal that those people witnessed back then,” Mr. Edwards said, speaking by phone from Los Angeles. So his design, to some degree, was a reverse-engineering job: building the creature that inspired the Toho movies.

Mr. Edwards said he figured that designing would be the simplest task, because, “everybody knows what Godzilla looks like.” He soon realized it was the most difficult part: “The problem is everybody thinks they know what Godzilla looks like. But it’s kind of like witnessing the scene of a crime, where your memory of it is slightly different than what you think.”