WMG / Where the Wild Things Are

The Wild Things are how Max views himself and the people around him.
Each one of the Things is either part of his personality, or someone in his life as represented in his little mind.
  • Carol: The most impulsive and immature Thing is supposed to be Max. This is how Max feels all the time.
  • K.W. is his mother and sister rolled into one. Her loving compassion towards Max is his mother, and her loner attitude and not wanting to be around the other Things is his sister. Both his mother and his sister love him dearly though, which is why they're one thing.
  • Douglas: Douglas is Max's moral code. Douglas is always there to calm Carol when he starts to act up, but it doesn't always succeed.
  • Judith: Judith is the first half of Max's temper. She is the anger, passion, energy, and drive inside of Max. Though she can be aggressive and demanding, she is also fun loving and willing to do things.
  • Ira: Ira is the Blue oni to Judith's Red Oni. He is the second half of Max's temper. He is calm, passive, nonchalant, and indifferent. Though he is calm and collected, he's also a push over and very passive. He is the recessive half of Max's temper.
  • Alexander: Alexander is how Max feels around bigger people. Alex, like Max, is constantly being ignored, belittled, and looked over by the others.
  • Bernard (the bull): Bernard is the suppressed sadness Max feels constantly. This is more than likely due to his father being no longer around, and his mother and sister being too busy for him anymore.

Max's mom works for Pixar
We hear her talking on the phone in one scene to a Mr. Lasseter. Perhaps she's taking a break from work?

Max had been kidnapped by a group of pedophiles
The Wild Things are just his image of them. They are a group of immature men and women who have nefarious plans, but they never got past the stage of giving Max everything he wants before Max escapes. If he would have stayed, he would have ended up "eaten" just like the other kids before him.

Max is a young John Cleaver
In the beginning, Max is displaying characteristics of burgeoning, neglect-defined ASPD such as impulsivity, acting out and violence as a way to get attention, and cruelty to animals. Like John, he acts this way because of family problems that aren't fully explained-it's only implied that his dad is thoroughly out of the picture. He hates people "looking at [him] like [he's] a bad person" and strives to be kind and brave, but often fails and ends up hurting himself or others.

While Max seems in a better headspace at the end, it often takes more than once to learn a lesson, leading to his mother taking him to a therapist and him getting diagnosed with conduct disorder.

Besides the uncanny physical resemblance, this also explains why John is so quick to accept that Crowley isn't human-he's seen fantastic Things before, so actual monsters aren't a stretch.

The Wild Things are Max's way of coping with his parents' divorce.
Specifically, Carol, a male Wild Thing who's immature and selfish but speaks with the voice of an adult man, is Max's dad and KW, a female who speaks with the voice of a mature and motherly adult woman, is Max's mom. Notably, Carol is incredibly resentful of KW for meeting new friends, the same way Max's mom seems to be interested in another man. And at one point near the end, Carol becomes incredibly angry and Max, and he lashes out violently, the way a father with too big a temper would lash out at a son who disappointed him. A bit later, Carol calms down a bit and manages to have a tense-but-meaningful conversation with KW, asking very soberly, "Am I as bad as he says I am?" or in other words, "Am I really a bad dad?" KW says just enough to placate him, and when he leaves, Max (who is literally inside her belly at this point — talk about your Freudian imagery) reminds her that Carol "really does love [her]," which only leads her to muse that "it's hard being a family sometimes." The language and the imagery are really overwhelming.
Max didn't get out of K.W.'s Stomach.
She kept him in there and the rest of the movie was his dying hallucination.