In ‘A Monster Calls,’ Liam Neeson voices a hulking tree monster who helps a boy cope with his mother’s illness. This can only happen in the movies, where trees have been known to meddle in the affairs of humans. Let's take a stroll through this peculiar forest, shall we?

The Fighting Tree in ‘The Wizard of Oz’ (1939)

While on her way the Emerald City, Dorothy forgets that she's not in Kansas anymore and attempts to pluck an apple from a tree... only for that tree to come to life, admonish her, and throw its own fruit at her in a fit of rage.

The Possessed Tree in ‘The Evil Dead’ (1981)

The horror genre has seen its fair share of nasty trees, but few have been quite as brutal as this one, which comes to life in the darkened forest and assaults an unsuspecting victim. Lesson learned: just don't go visiting abandoned cabins in the middle of nowhere – there could be evil trees afoot.

The Backyard Tree in ‘Poltergeist’ (1982)

While the entire movie is frightening, 'Poltergeist' will be forever known as the movie that confirms what you always knew deep down in your soul. Yes, that creepy tree in the backyard is evil and yes, it will try to eat you in the middle of the night.

Grandmother Willow in ‘Pocahontas’ (1995)

While most living trees seem to have a beef with humanity, Grandmother Willow exists to bring people together, acting as a wizened advisor to Pocahontas and offering sage advice when her people find themselves on the brink of war with English settlers.

Treebeard in ‘The Lord of the Rings: The Two Towers’ (2002)

J.R.R. Tolkien was a lover of nature and the adaptations of his beloved novels bring one of his greatest visions to life: the Ents (and specifically the long-winded Treebeard), sentient trees who join the War of the Ring after the evil Saruman destroys large swaths of the forest.

The Whomping Willow in ‘Harry Potter and the Prisoner of Azkaban’ (2004)

The Hogwarts School of Witchcraft and Wizardry is a dangerous place by default, but it's especially dangerous when you wander near the edge of the grounds, where an animalistic tree hell-bent on pummeling everything that comes near has been planted. And yes, this pugilistic tree is here for a reason...

Groot in ‘Guardians of the Galaxy’ (2014)

Look, a 12-foot tall walking tree that can only mutter "I am Groot" (even as he's impaling an army of henchmen with his spindly arms) shouldn't be this adorable. Then again, 'Guardians of the Galaxy' is a movie filled with all kinds of surprises.

The Monster in ‘A Monster Calls’ (2016)

We all grieve in different ways. Sometimes, we work through our issues with the help of a giant tree monster that speaks in the voice of Liam Neeson and dispenses cathartic advice through seemingly random stories that actually serve as metaphors for your personal pain. The more you know!