Prince Herneval (voice of Arturo Mercado Jr.) and Frankelda (Mireya Mendoza) in "I Am Frankelda."

Netflix

Little did brothers Roy and Arturo Ambriz know that nearly two decades after Roy emailed Guillermo del Toro for advice, the iconic filmmaker would champion their stop-motion animated work, including the new film I Am Frankelda.

“I sent the email to him 17 years ago before I started filmmaking. I took the same course that he took with Dick Smith, the makeup FX artist from The Exorcist, when he was younger,” Roy Ambriz recalled in a Zoom conversation, alongside Arturo Ambriz, on Wednesday. “So, I wrote fan mail to show him the work that I was doing at that time and he answered back."

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What began as correspondence between the Ambriz brothers and del Toro turned into a mentorship that has continued to I Am Frankelda and beyond — resulting in opportunities the filmmakers never could have dreamed about 17 years ago.

“Now that we’ve finished the film, that relationship has grown a lot stronger,” Roy Ambriz noted. “He invited us to go with him to London when he was doing the score at Abbey Road Studios for Frankenstein with Alexandre Desplat, and then he invited us to go with him to Canada when he was doing the sound mixing of Frankenstein. We have learned a lot from him.”

Written and directed by the Ambriz brothers, I Am Frankelda (Spanish title: Soy Frankelda), which is a prequel film to their 2021 stop-motion series Frankelda’s Book of Spooks, premieres on Netflix on Friday. Set in 19th-century Mexico, I Am Frankelda follows a young writer, Francisca Imelda (voiced by Mireya Mendoza), who has a clear gift of writing dark tales but is discouraged by everyone but her dying mother to put the soul that is the ink of her pen to paper.

As an 18-year-old, Francisca — frustrated by those who are trying to suppress her voice after her mother’s passing — combines her first and last name and dubs herself “Frankelda.” From there, Frankelda takes a trip from the Realm of Existence to her subconscious and the Realm of Terror, where the monsters she created in her mind and given souls on paper have come to life.

Existing as a spectral figure in the Realm of Terror, Frankelda encounters Herneval (Arturo Mercado Jr.) — a prince trapped between the world of dreams and nightmares — who is trying to restore balance between the fictitious and real-world realms before they collapse.

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If the plight of the young writer who creates monster tales sounds familiar, it’s not a coincidence that the Ambriz brothers rooted the motivation of the title character in I Am Frankelda in the real-life story of Mary Shelley, who at age 18 wrote the landmark novel, Frankenstein.

Because she was a female writer, Shelley wasn’t initially credited as Frankenstein’s author when it was first published in 1818, and had to wait five years until her name could became attached to the novel in 1823. Since then, Shelley’s classic story has been adapted for the screen hundreds of times — including del Toro’s Oscar-nominated feature iteration released by Netflix in 2025.

“We started playing with the idea of, ‘What would have happened if Mary Shelley was born in Mexico? Would it have been easier with it having more difficult [for her to publish Frankenstein]?’ and our conclusion was, “I think that it would have been impossible for her to publish her work, so she would have to come back as an angry ghost,” Arturo Ambriz explained.

“She’s filled with frustration and creativity, so that’s the character we wanted — an angry ghost,” Roy Ambriz added. “We didn’t really try to make a movie about Mary Shelley’s works or life, but about her essence as a woman writer, young, full of energy and full of creativity, and wanting to challenge the entire world and be able to write her own stuff.”

In a wonderful twist of fate, I Am Frankelda and del Toro’s Frankenstein were both released on the same day in Mexico, on Oct. 23, 2025.

“It was a big phenomenon here in Mexico. It was like an event when Barbie and Oppenheimer were released, and everybody was going to watch both films on the same day,” Roy Ambriz enthused. “Fans started creating artwork in which Frankenstein and Frankelda were interacting, so it was a blast. We had a toast with Guillermo for both of the Franks.”