Little Otik

"Little Otik" ("Otesánek") is a 2000 Czech movie by acclaimed film director and animator Jan Svankmajer. The film is a combination of live-action with animation and is based on a traditional Czech fairy tale about a childless couple who adopt a tree stump who later becomes alive. After a while this humanoid tree transforms into a hungry giant monster who eats everything in sight. Svankmajer modernizes the story to an infertile couple in the late 20th century The Czech Republic who treat a tree stump as their own child. They keep this a secret from the rest of the people who live in their apartment block. One little girl, Alžbětka becomes suspicious and actually makes the link between the fairy tale and what is happening in real life...

Relevant tropes:

 * Animate Inanimate Object: Little Otik originally started out a vaguely human-looking tree stump, until the woodcutter chopped off the extra roots and presented it to his overjoyed wife, and for one reason or another, Otik gains sapience.
 * Be Careful What You Wish For: The couple wanted a child and they got one, humanity notwithstanding.
 * Babies Make Everything Better: Subverted like a cancer.
 * Big Eater: Otik will eat practically anything edible: milk, a whole field of cabbages, animals, his mother's hair....his mother.
 * Cool Old Lady: Paní správcová, who finally decides to dispatch the man-eating giant Otik with a hoe after it devours her entire cabbage patch. Her name even means 'porter's wife' or 'old woman'.
 * Creepy Child: Despite being more akin to a tree/humanish hybrid, Otik definitely qualifies. Also Alžbětka, the neighbor's daughter, who looks after a gigantic man-eating Otik after Otik is locked away by his father.
 * Dirty Old Man: Mr. Žlábek, the pedophile who likes to stare underneath the skirt of the neighbor's daughter. He gets eaten by Otik.
 * Kids Are Cruel: The girl allows Otik to eat Mr. Žlábek and Otik's adoptive parents.
 * Man Eating Plant: Little Otik. As he gains size, the not-so-little Otik begins to desire more than just milk...
 * Oh Crap: From one commentator, when the husband sees the wife treating the tree stump he gave her as if its an actual baby - 'Ohhh god, it never fails to amuse me how the husband's expression changes once he witnesses his wife's reaction to the 'tree baby'. First he's like: hahahaha isn't he cute honey, I thought﻿ this would cheer you up a bit and make you laugh.... then seeing her reaction, he's like: Oh shit! What have I done!? My wife.... is a nutter *__* LMAO.
 * Only Sane Man: The woodcutter, who is immediately aware that Otik (whom he made from a tree stump to appease his child-desperate wife) is not the little bundle of joy his wife thinks it to be. This still doesn't help him though because, when he finally decides to confront and destroy the gigantic, chained Otik in the basement with a chainsaw, upon gazing at the monstrosity, he stops what he's doing and longingly calls it 'son' before he, too, is devoured.
 * Piggy Bank: The little girl in "Little Otik" destroys her piggybank to get the money inside.
 * Uncanny Valley: Other than his shape (and little root penis), Little Otik looks nothing like a human baby other than his mouth whenever he decides he (it) wants to eat and make baby-ish noises. This, juxtaposed with his eyeless head and jerky stop-motion, makes one wonder just how desperate (or sane) the wife had to be to 'adopt' him.
 * Weirdness Censor: The wife. Not only does she find it not strange that a human-shaped tree trunk came to life for no explicable reason, but she appears to see nothing wrong when it begins to crave more food, eats her ponytail (which she covers up as giving herself a new facial improvement), and feeding it raw meat. Her desperate desire for a child, however, may be covering up her common sense and putting her in denial.
 * The Woobie: Despite her being the cause of all the mess, the wife's deep desire for a baby of her own makes her this.