Director Guillermo del Toro said about Sally Hawkins, "Not only was she the first choice, she was the only choice. I wrote the movie for Sally, I wrote the movie for Michael [Shannon]... Sally is, I wanted the character of Elisa to be beautiful, in her own way, not in a way that is like a perfume commercial kind of way. That you could believe that this character, this woman would be sitting next to you on the bus. But at the same time she would have a luminosity, a beauty, almost magical, ethereal."
The creature design is heavily inspired by the film The Creature from the Black Lagoon (1954). Michael Shannon's character even says they picked it up in a river in South America, which is the setting of The Creature from the film.
Most of the characters were written with the actors in mind. Octavia Spencer said her character was reminiscent of a collaboration between her roles in The Help (2011) and Hidden Figures (2016), and that she "would have played the desk if Guillermo del Toro had asked me to."
Director Guillermo del Toro first met Sally Hawkins at the 2014 Golden Globes and pitched the film to her while being intoxicated. He says, "I was drunk and it's not a movie that makes you sound less drunk."
According to Danish DP Dan Laustsen, 95% of the film was shot in a studio, and the limited exteriors required lots of rain which had to be artificially created and warmed due to the chilly Canadian winter weather.
With the release of Maudie (2016) the same year, this marked the first time Sally Hawkins was the lead in two theatrical releases within the same year. In both films, she portrayed a woman with a disability. In Maudie (2017), her character suffers from a result of juvenile rheumatoid arthritis, and in The Shape of Water (2017), her character Is mute.
A series of photos depicting artist James Jean's progress on the poster artwork can be found on his Instagram page. On two such photographs, reference photos of the creature can be seen in the corner, presumably unreleased stills from the actual movie.
This was the third collaboration between director Guillermo del Toro and composer Alexandre Desplat, but their first film with del Toro as director. The composer previously provided the music for the del Toro-produced animated movie Rise of the Guardians (2012), and he scored some of the del Toro-penned and produced animated series Trollhunters (2016).
The film is considered to be a retelling of "The Beauty and the Beast" by Jeanne-Marie Leprince de Beaumont. The film is the story of a mute woman working in a high-security government laboratory whom falls in love with a captured amphibian creature.
One of the main characters, played by Richard Jenkins, is an artist and has a drawing of Audrey Hepburn in his studio. Sally Hawkins played a woman named Elisa in this film, and Audrey Hepburn played a woman named Eliza in My Fair Lady (1964).
The trivia items below may give away important plot points.
Elisa was a left as a foundling baby by a river, is mute like the Amphibian Man, prefers to express her sexuality in water, and lives in a home with scale-print wallpaper. All these point to the fact that the marks on her neck were never scars, but are undeveloped gills, suggesting that she is descended from someone like the Amphibian Man.
One of Octavia Spencer's favorite things about the screenplay was the fact that, by letting the main couple be mute, most of the dialogue comes from a black woman and a closeted gay man. In real life, they would both have experienced suppression during the 1960s setting of the film.
The dance scene between the creature and Elisa is an homage to a dance scene between Fred Astaire and Ginger Rogers in Follow the Fleet (1936). The unusual set piece is the same as the one seen when Fred sings Let's Face the Music and Dance.
The top billed movie playing in the theatre over which Ella lives is The Story of Ruth. One would suggest that by choosing that film del Toro was slyly telegraphing the film's ending. In the Biblical Book of Ruth, young Ruth, just widowed, tells her mother-in-law, Naomi, "Wither thou goest, I will go. Wither thou lodgest, I will lodge." Precisely the final end of the film.