Victor Frankenstein's laboratory and Captain Anderson's ship were fully constructed sets. "I want real sets", director Guillermo del Toro explains. "I don't want digital, I don't want AI, I don't want simulation. I want old-fashioned craftsmanship: people painting, building, hammering, plastering."
For his role as the Creature, Jacob Elordi studied Japanese butoh dance (a form that involves undignified poses and dark themes) and Mongolian throat singing to capture the Creature's mannerisms.
Playing Frankenstein's creation was the most demanding role of Jacob Elordi's career. He spent up to ten hours in the makeup chair for extensive makeup application. To make his early call time, he'd sometimes arrive at the makeup trailer at 10 P.M. and stay up all night. Director Guillermo del Toro says he came to believe Elordi was "superhuman". "Never once did he come to me and complain", del Toro marvels. "Never once did he come to me and say, 'I'm tired. I'm hungry. Can I go?' And he put in 20-hour days." Elordi loved the experience. "It's the most I've felt at home, ever, playing a character and shooting a movie", Elordi admits. "It was the most comfortable I've ever been."
Andrew Garfield was originally cast as the Creature, but had to drop out due to scheduling conflicts. He was replaced by Jacob Elordi in the role. The makeup team spent nine months crafting Garfield's look as the Creature, but had only a few weeks to rework it for Elordi in time for filming.
Artist Bernie Wrightson, who drew the illustrations of the 1983 "Frankenstein" graphic novel on which the Creatures design is based in the film, was a close friend of the film's director, Guillermo del Toro. del Toro licensed Wrightson's illustrations of the Creature before the film's pre-production.