*WARNING* Spoilers 

This is an Australian Psychological Thriller about a monster that comes to life from a children's book that mysteriously appears in this child's bedroom. 

The story focuses around Amelia and her 6 year old son, Samuel. In the backstory we discover that Amelia's husband, Oliver, was killed in a car accident while the couple was on their way to the hospital to give birth to Samuel. Amelia clearly has not gotten past this event and we see her progressively looking more and more tired and run down. Of course I would be tired and stressed out too if I had a child that bratty (seriously I hate this kid!). Samuel barely sleeps, he runs around with this contraption he built to kill monsters with and to me it looks like one of those automatic baseball pitchers they have at batting cages. His cousin's princess birthday party is ruined when Samuel breaks the girls nose in 2 places after he pushes her and she falls out of her tree house, after taunting Sam about how his dad died so he didn't have to be around him. The little girl had it coming, but that's just me. 

One night when Amelia is reading a story to Sam, they find this book in his room called "Mr Babadook" it appears to be a children's pop up book...if you never want your child to sleep again. Seriously? A children's book?  Grimm's fairy tales are dark but this is just ridiculous. Amelia stops reading when she figures out this is no children's book and Samuel proceeds to have a temper tantrum (as he does about 5 times in the movie). I mean an all out 2 year old, throw myself on the floor kicking and screaming temper tantrum.  One of his tantrums causes him to have a seizure which lands him in the hospital, with his mother begging the doctor to prescribe her son sedatives so she can sleep, which he does. 

For the next few days, we watch Amelia's rapid decent into madness. She destroys the book, throws it in a dumpster and the next morning it is on her front step, taped back together and it seems the words have changed and become more sinister. This time she burns it and attempts to file a police report which is not received well. 

Amelia returns home and finds nasty looking bugs crawling out of her walls. 
She has morbid visions about killing the family dog and she hallucinates a news story about her killing her son and then herself. We knew from the beginning that Amelia wasn't well, you can see it on her face and you can see that somewhere in a dark part of her brain, she blames Samuel for his fathers death. So she has some things going on, clearly. 

One night, Amelia wakes up and sees this black humanoid-arachnid type thing crawling on the ceiling and it appears to possess her. Now Samuel and the dog appear to be terrified of her as they peek around a corner to spy on her. The dog starts barking  at her, which agitates Amelia and she chases it into the kitchen where she snaps it's neck (poor doggy didn't do anything to her) this is the beginning of the climactic ending that appears to be a game of tug of war between an actual monster and the mothers psychological decent into some serious schizophrenic episodes. 

Nobody really wins in the end because you can't get rid of the Babadook. Clearly there was an agreement made to allow this thing we never see to live in the basement and eat worms that Amelia brings it every day. Is this symbolic? Is this a woman that has overcome her illness and is keeping the monster inside quiet by feeding it medication?  I only ask this because she appears to be happy in the end for the first time in the whole movie. 

So the Babadook represents a severe mental illness that she let in by not opening dealing with her loss and letting it send her into a downward spiral that could have led to a violent end for both her and her son. 

That's what I got out of it. 

This is why they are called Psychological Thrillers.