When it came to dreaming up characters of cheeky grandiosity who were put on earth to act out their fear and loathing of children, Roald Dahl didn’t play. In 1961, his first classic novel, “James and the Giant Peach,” featured the loathsome Aunt Sponge and Aunt Spiker, who tormented James like nightmare Victorian spinsters out of Dickens. The title character of “The Enormous Crocodile” wants nothing more than to chomp down on children. In “Matilda,” Miss Trunchbull is a school headmistress so sadistic she’s like a bullying tyrant out of Pink Floyd’s “The Wall.” And in “Charlie and the Chocolate Factory,” even that rock star of candy Willy Wonka can’t seem to make up his mind about whether he wants to delight children or unsettle them. But in “The Witches,” Dahl really went all out. The book is a primal fairy tale, part Grimm and part flamboyant kiddie opera, about an orphan vacationing with his grandmother at a majestic hotel, where he has a run-in with a coven of witches. They’re attending a meeting presided over by the Grand High Witch, a preening fascist harpy who possesses a potion that can turn children into mice (which she wastes no time doing). Her signature trait, however, is the deluxe hatred that pours out of her like poison. Did Roald Dahl have some deep-seated personal issue (he spoke of the abusive behavior he experienced at boarding schools), or was he just a storyteller with the courage to create unbridled wackjob kiddie villains? Maybe a little of both. In the 1990 screen version of “The Witches,” directed by Nicolas Roeg, the Grand High Witch was played by Anjelica Huston in a performance of pure delectable scenery-eating kitsch. She was a comic foil out of Mel Brooks, and also the purest of monsters. Thirty years later, Robert Zemeckis has now directed a version that remains true to the novel (and also builds on the earlier film), and what he brings to it is his fusion of relatability and FX gizmo play. It’s nothing more than a baroque cartoon horror film (it stays right on the surface), but the best parts have a crackpot malevolence that’s hard to resist. Anne Hathaway, as the Grand High Witch, has been outfitted with a set of severe nightmare trappings that are sure to frighten little ones: a bald head concealed under a series of wigs that cause her to have a terrible scalp rash; arms that stretch out into groping mangled claws; a long middle toe on an otherwise truncated foot; and, most strikingly, a mouth extended back by scars (just like the Joker’s), which gives her an enlarged smile as creepy as the ones in the 1994 David Lynchian music video for Soundgarden’s “Black Hole Sun.” The triumph of Hathaway’s performance is that she never allows the visual effects to dominate her; she acts from inside them, wearing them like makeup. Speaking in an accent that’s like Boris and Natasha by way of Donald Trump’s wives (“Vut vould you do if dere ver mice running all around dis hotel?”), she gives a seething performance that’s two parts “Mommie Dearest,” two parts Wicked Witch of the West, one part “Alejandro”-era Lady Gaga cranking up all the stops, one part Divine, and two parts meth junkie. It’s a whale of an over-the-top turn, one you can sit back and revel in just for how she pronounces the word “garlic” (“goooord-lick!”). She makes Angelina Jolie’s Maleficent look like a wallflower. She’s high-camp funny but also genuinely threatening. The rest of “The Witches” is serviceable in a standard hellzapoppin’ way. For a while, it feeds on the audacity of transplanting the story to the American South, where our hero (Jahzir Bruno), an 8-year-old child in Demopolis, Alabama, in 1968 (in the credits he’s referred to simply as “Hero Boy”), loses his parents in a car accident and moves in with his warm, wise, whiskey-swilling Grandma (Octavia Spencer). She tries to lighten his mood with fried chicken and cornbread and Motown tunes, but once they arrive at the Grand Orleans Imperial Island Hotel, a swank getaway set behind a curtain of magnolia trees along the Gulf of Mexico (her cousin is the executive chef there), the film mostly loses its real-world sense of period. There’s one eye-catching set: the Grand Imperial Ballroom, which looks like the Sistine Chapel by way of “The Shining.” It’s where the witches let their hair down, literally, under the guise of holding a convention of the International Society for the Prevention of Cruelty to Children. And it’s where our hero gets vaporized by a vial of purple potion and turned into a mouse. So does Bruno (Codie-Lei Eastick), a face-stuffing British kid, and Daisy (Kristin Chenoweth), the hero’s pet mouse, who it turns out has already been the victim of this transformation. The three are now CGI rodents scurrying around the ornate ledges and kitchen shelves of the hotel like something out of “Mousehunt” or “Ratatouille.” These scenes are fun in a logistically energized but slightly flavorless way. You could say that “The Witches” doesn’t have much in the way of emotional pull, and that there are too few layers to its battle against evil. Yet Anne Hathaway’s performance provides the film with a sick-joke center of gravity, and Zemeckis, sticking to Dahl’s elemental storyline, stages it all with a prankish flair that leaves you buzzed.