Philip Booth is a movie reviewer and film essayist.

The ghastly creatures — Dracula, Frankenstein, the Werewolf and others — in the old-school monster movies from Universal Pictures scared audiences in the 1930s and 1940s.

So, too, did the Gill-man from 1954’s “Creature From the Black Lagoon,” said to be inspired by stories of a half-human, half-fish monster living in jungle rivers. But the Gill-man was all make believe, right?

“It seemed plausible,” Mallory O’Meara, a screenwriter, film producer and co-host of the literary podcast “Reading Glasses,” writes in “The Lady From the Black Lagoon: Hollywood Monsters and the Lost Legacy of Milicent Patrick.” “An amphibian missing link? No less crazy than a human going into space.”

Lurking off screen, though, was genuine horror for the careers of creative women working behind the camera in the boys-club confines of Old Hollywood. Hidden from public view — but doing far more long-term damage than the fainting spells occasionally suffered by audiences of scary movies — was the lack of credit given women for their often innovative work.

Milicent Patrick, an artist at Universal who had also made minor screen appearances, found herself in the limelight as the creator of the beast in “Creature From the Black Lagoon.” Patrick, as O’Meara carefully documents, essentially masterminded the look of the scale-covered, fearsome but oddly sympathetic creature that emerged from the Amazon River — or rather, Florida freshwater springs — in a movie that generated about $12 million domestically (in today’s dollars) and became a cult classic.

She studied illustrations of prehistoric animals, made sketches and submitted her designs to the sculptor, Chris Mueller. Later, he said Patrick deserved credit as the chief architect of the creature. His view, in O’Meara’s telling, was that “the Creature, the whole monster, was designed by Milicent, who had been working on it as soon as it was assigned to the makeup department.” She also designed masks and/or monsters for 1950s releases “It Came From Outer Space,” “This Island Earth,” “Abbott and Costello Meet Dr. Jekyll and Mr. Hyde” and “The Mole People.”

Patrick parlayed her striking looks and natural charisma into at least 15 uncredited movie appearances, one small credited film role and a half-dozen TV roles. But only in recent years has she received her due as a master monster-maker.

“Why is she the only classic monster designer . . . that people deem unlikely? Because she is, well, a she,” O’Meara writes of an industry that more than six decades later still struggles to let women and minorities access high-profile opportunities behind the camera.

O’Meara’s book, published to coincide with the 65th anniversary of the national release of “Creature From the Black Lagoon,” arrives amid a resurgence of appreciation for the horror classic, sparked in part by remembrances of Julie Adams for her leading role. There is a special screening planned in April at the Chattanooga Film Festival and unconfirmed social media buzz about a possible remake. Not to mention the Oscar-winning success of Guillermo del Toro’s critically acclaimed “The Shape of Water,” a magical, moody 2017 horror and interspecies-romance tale centered on a creature directly descended from the Gill-man.

Like the creature, “The Lady From the Black Lagoon” is a hybrid — part biography, part memoir, part detective story and part #MeToo pushback against the film industry’s deep-rooted patriarchal tendencies, highlighted in revelations of sexually predatory behavior by male actors, directors and moguls. Divided into chapters named for filmmaking terms, with footnotes functioning as often-cheeky asides, the book crosscuts episodes from Patrick’s life with sequences from the author’s own background as a goth and self-described “monster nerd.” Along the way, she offers clear explanations of various aspects of moviemaking.

O’Meara’s fascination with fright films began when, as a child, she saw the giant demon Chernabog in the “Night on Bald Mountain” segment of Disney’s animated anthology film “Fantasia.” Her passion serves her well in sketching Patrick’s life. Patrick was born Mildred Elisabeth Fulvia Rossi in 1915 in El Paso. She grew up in Northern California near the 128-acre Hearst Castle estate, where her father, Camille, served as construction supervisor for newspaper magnate William Randolph Hearst’s palatial home.

In the late 1930s, Patrick became one of the first female animators for the Disney studio in Los Angeles, where she worked on “Fantasia” and “Dumbo,” among other films. She subsequently modeled, picked up jobs as a background movie actress and freelanced as a visual artist focused on special effects at Universal’s makeup department, headed by the mercurial but well-regarded Bud Westmore.

Horror buffs are likely to be most enthralled by O’Meara’s account of the genesis and development of “Creature From the Black Lagoon,” inspired by a concept brought to Universal by producer and writer William Alland; his first script treatment was titled “The Sea Monster” and essentially was “King Kong” set in a river, featuring a beast that was less beastly than dignified, and barely recognizable as a monster.

Like the script, the creature suit — worn by two different actors — evolved extensively and initially resembled a sad-looking fish. Patrick reconceived the water-born monster as covered in scales, something “more menacing, more primordial, more powerful,” as the author describes it. “Fanning out from the side of its neck were thick gills, protruding from a bald, textured head with a prominent brow and thick, fleshy lips.”

Given her obvious appeal as the dynamic, photogenic artist who was responsible for the Gill-man’s design, Patrick was asked to travel the country promoting the film, which was shot in black-and-white and released in 3D. Patrick’s tremendous success on the tour, originally to be called “The Beauty Who Created the Beast,” ironically led to her firing from Universal: Her boss, Westmore, apparently wasn’t keen on letting an employee receive full credit for work done under the aegis of the department he ran, and by all accounts he hated Patrick’s new role as the face of fawning press coverage of the movie’s release.

In later years, Patrick had another life as a socialite, throwing elegant parties at the large home in Sherman Oaks, Calif., she sometimes shared with businessman husband Lee Trent and raising funds for various causes. Her brilliant career makes for an often-fascinating life well told by O’Meara, who views Patrick as something of a groundbreaking role model for the author’s own path as an artist and advocate for female empowerment in Hollywood: Patrick’s legacy, she writes, “continues in all of the women who saw her contribution to film history and realized that they could do it, too.”

The Lady from the Black Lagoon

Hollywood Monsters and the Lost Legacy of Milicent Patrick

By Mallory O’Meara

Hanover Square. 330 pp. $26.99