Amy Adams turns into a dog in 'bizarre and brilliant' film

A new film starring Amy Adams as a mother who thinks she's turning into a dog at night has received its UK premiere at the London Film Festival.

Nightbitch, based on the 2019 novel by Rachel Yoder, is a film that may sound bizarre on paper, but is intended more as a metaphor for the nature of motherhood.

Adams plays an unnamed woman who quits her job as an artist to be at home full-time with her young son while her husband continues working.

But she finds herself increasingly identifying with the behaviour of dogs - acting on her feral instincts and being fiercely protective of her offspring.

The film has been described by Entertainment Weekly's Maureen Lee Lenker as "a playful, creative, and brutally honest portrayal of being a mom".

"This isn’t a movie about how parenting will ruin your life," noted Vanity Fair's Hillary Busis, "but it does tap deeply into how monotonous it can be to care for a small child.

Nightbitch, set to be released in December, is directed by Marielle Heller, the film-maker behind A Beautiful Day in the Neighbourhood and Can You Ever Forgive Me?

Her latest feature has minor elements of body horror - the mother grows fur, extra nipples and a tail - but is a walk in the park compared with Demi Moore's recent film The Substance.

Adams has previously starred in films including Arrival, Nocturnal Animals, American Hustle, Dear Evan Hansen, Vice and The Woman in the Window.

Heller and Adams walked the red carpet ahead of Nightbitch's UK premiere at London's Royal Festival Hall on Wednesday.

In an interview with Vanity Fair, Adams said she thought Yoder's novel was "unique and otherworldly, and like nothing I'd ever read before", adding: "The thing I really attached to is this idea of loss of identity."

Reflecting on her character's journey in the film, Adams explained: "Through her parenting - through her mothering - she got in touch with something bigger and something primal."

The 98-minute film has received broadly positive reviews, although some critics suggested not every idea explored in the film fulfils its potential.

"Part of the brilliance of Nightbitch," Lenker said in her review, "is the ways it doesn't stop at showcasing the isolation and loneliness of motherhood, cut off from a previous version of oneself and one's life. It takes this fable a step further."

She described Heller and Adams as "a dynamic pair, finding ways to punctuate their bizarre tale with brutal honesty, off-the-wall humour, and a desire to celebrate the messiness and magic of motherhood".

"Loving your child but hating motherhood is a conflict that Heller captures with an honesty that we often don’t see," noted Pajiba's Sara Clements.

"Mother is a character whose transformation presents a rawness in its unglamorous truths, with Adams delivering a beast of a performance."

Jourdain Searles of Little White Lies added: "As corny as Nightbitch can be, there's no denying the universal truths behind the narrative."

Elsewhere, Nadia Dalimonte of Next Best Picture wrote: "While Heller struggles to balance the visual concept with its philosophical themes, her compassionate sensibilities bring Nightbitch home."

However, Natalia Keogan of the AV Club said the "mundane" film somewhat underdelivered on its potential.

"It’s normal to become excited when one's experience appears to be accurately represented on screen, but a successful film needs to be more than merely a mirror," she said.

"While it emphasises the unsung and vital presence of mothers, Nightbitch doesn't probe the broader societal devaluation that actually causes women to feel unfulfilled."