The film centers on Tinja, a young gymnast desperate to please her mother, a woman obsessed with presenting the image of a perfect family to the world through her popular blog.

Once it hatches, she names the creature within "Alli", and cares for it as it grows into a doppelgänger that acts upon Tinja's repressed emotions.

[4] Twelve-year-old Tinja practices gymnastics, an activity imposed upon her by her image-obsessed mother, a former figure skater turned influencer.

She brings the crow's orphaned egg home and incubates it underneath a pillow, and later, as it grows larger, inside a large teddy bear.

Returning home one day from gym practice, Tinja discovers Mother is having an affair with her handyman, Tero.

The egg eventually hatches into a bizarre, bird-like creature, which soon escapes, returning the next evening with a lingering injury from a shard of glass.

Tinja hastily buries Roosa in the backyard, unaware that her younger brother, Matias, is watching her.

Later, Tinja brings Reetta flowers, horrified by the severity of her injuries and amputated left hand.

Tinja collapses onto Alli and dies, her blood falling into the creature's mouth and completing its transformation.

Brad Miska of Bloody Disgusting commented on the trailer, comparing it favourably to the 1990 film Meet the Applegates and writing that it "sits comfortably toward the top of my must-see list.

"[13] IndieWire's Eric Kohn also made mention of the film in their list of Cannes 2021 predictions, writing that it "could appeal to fans of the Swedish monster movie, Border — which won the Un Certain Regard prize at Cannes in 2018 — but with an extra dose of commentary of the social media curation of one's lives so many of us engage in.

The website's consensus reads: "A message movie with a hard horror shell, Hatching perches between beauty and revulsion – and establishes Hanna Bergholm as a bright new talent.

"[15] Metacritic, which uses a weighted average, assigned the film a score of 75 out of 100, based on 25 critics, indicating "generally favorable" reviews.