Movies, even fairy tale adaptations, have taken to coddling kids — fretting more about offending than worrying if they’re challenging.

“A Monster Calls” upends some of that conventional focus-group wisdom. Here’s a child’s fantasy that is as amusing as it is disturbing, a seriously unsettling take on childhood trauma whose horrors are based on the ultimate childhood fear — losing a parent.

Conor O’Malley (Lewis MacDougall) is “a boy too old to be a kid, too young to be a man,” our narrator tells us. At 12, that is exactly who he has to be — self-starting, self-reliant, dressing himself for school, making his own breakfast, straightening up the house.

Conor’s world is dominated by the sleepless coughing in the next room, the prescription medicines he has to understand more than any 12-year-old should. His mother (Felicity Jones) has cancer.

He’s bullied at school, a lonely, bruised and humiliated child who loses himself in his iPod and his drawings. But those drawings are his coping mechanism. He dreams each night that the nearby church and its graveyard collapse into a sinkhole, with only his screams and his clinging hand keeping his mother from the abyss.

He draws a monster out of the churchyard’s ancient yew tree, a Groot/Treebeard behemoth with the growl of the grandfather (Liam Neeson) he never knew and the unsentimental tough-love of a missing role male role model, the kind he doesn’t have in his life.

Then the monster rumbles into his yard, smashing fences and masonry as he does, and informs the boy that he will tell him three stories, and at the end of those, Conor must return the favor and tell a tale that “reveals your truth.”

Every night at 12:07 Conor faces his demons and this monster as the beast relates oblique parables about faith, empathy, the torture of being invisible, of showing care when judging people.

“There is not always a good guy, Conor O’Malley. Or a bad one.”

Is his grandmother (Sigourney Weaver) really the “witch” she seems to be? Are we ever truly able to conquer bullies — who always come in teams of three in the movies?

The stories, little fairy tales presented as marvelous 2-D watercolor animations or 3-D stop motion ones, are meant to teach. But Conor isn’t having it, relenting to hearing each one with the classic British sarcasm.

“Go on, then.”

He is inured to the violence of a medieval story, which appears to be about revenge but is much deeper than that, the monster intones. Conor has “never heard the screams of a man killed by a spear.” Every parable the monster resolves with his own intervention.

“I came walking.”

Meanwhile, the kid’s real world is entering its death throes — a spiral of rage, resentment, terror and guilt.

Director J.A. Bayona (“The Impossible”) doesn’t sugar coat the Patrick Ness novel. This is kid-lit with adult tones and textures. There’s sensitivity, but the harsh edges aren’t rubbed off for kid-safe consumption.

Yes, it’s the movie that the bloated, sentimental “The B.F.G.” should have been. But parents will be wise to spare kids under the age of 8 the traumas shared here.

Young MacDougall is a haunted-looking Brit, a child whose baleful stares should warn bullies that he’s the sort you will eventually need to outnumber when he has finally had enough.

Jones (“Rogue One”,”The Theory of Everything”) is an empathetic marvel, playing a woman who wants to protect her child from awful news, straining to maintain a brave face when the ravages of her disease make that impossible. Weaver is given to “no nonsense–we need to have a talk” role, and she plays its surprising dimensions with care and skill, if not the accent required.

Bayona enlists his movie’s stars and a forlorn monster in his movie’s melancholy, and even when we see where everything is going long before we get there, that mood and tone envelops us, prepares us the way Conor is being prepared — by his monster — for the future.

It’s isn’t for the very young or overly sensitive, faint-of-heart child. But “A Monster Calls” makes a case for remembering that fairytales can terrify as they teach and test us. We’re not really doing our children any favors by sanitizing life, even the fantasy version of it given to us in the movies.

MPAA Rating: PG-13 for thematic content and some scary images

Cast: Lewis MacDougall, Felicity Jones, Sigourney Weaver, the voice of Liam Neeson

Credits: Directed by J.A. Bayona, script by Patrick Ness, based on his novel. A Focus release.

Running time: 1:48