The huge box office success of 2017's IT renewed interest in one of Stephen King's most iconic creations, the demented, dimension-hopping monster that likes long walks in the sewer and dining out on scared human children. The titular creature is referred to -- for lack of a better description -- as "It" or "IT" in the original 1986 novel. From the passing of the Bradley Gang in 1929 onwards, witnesses to the monster's feeding frenzies reported seeing a red-haired clown in a silver suit amongst the carnage, and while It can take any form of its choosing, Pennywise the Dancing Clown became its favorite persona, one that enables it to pass through crowds in plain sight and has easy access to unsuspecting kids. It sometimes uses the name Robert "Bob" Gray, too.

To avoid the headache of "its" and "Its," we'll be using Its chosen Pennywise monicker from this point on. Both the 1990 miniseries and the 2017 movie did a horribly good job at conveying the sheer horror of Pennywise, which, if we're being honest, isn't too difficult considering clowns are naturally freaky anyway. Add a raspy voice and a massive mouth full of fangs into the mix and it's no wonder Pennywise is up there with some of the genre's most enduring icons, and the bane of every real-world clown's professional existence. As bizarre as things get on-screen during Pennywise's encounters with the Losers Club, for non-King-ophiles, these adaptations only really scratch the surface of how cosmically weird the hungry clown really is.

20 THEORY: PENNYWISE IS IN THE SHINING

hedge-maze-shining

Most King fans know that the father of IT's Mike Hanlon was friends with Dick Hallorann from The Shining, but there's an interesting theory that deepens the connection even further. A video essay by The Film Theorists explores how being able to "shine" -- a term for being psychic in the King world -- is shared by The Shining's Danny Torrance and the Losers Club.

This ability is perhaps the only thing the interdimensional terror fears, but the theory goes even further to suggest that not only does Pennywise's kryptonite feature in both tales, but that the ghostly apparition that convinces Jack Torrance to go ax-crazy is Pennywise -- up to his usual shapeshifting tricks; a trick it also uses on an adult Henry Bowers in IT.

19 TRUTH: PENNYWISE CONNECTS KING'S MULTIVERSE

It's not just The Shining that has strong ties to IT. Long before the shared cinematic superhero universes of Marvel and DC, King was scattering clues through his various books for decades that thread his disparate stories of dread and mysticism together. As one of his most recognizable creations, Pennywise gets a name-drop in at least half a dozen.

These include Gray Matter, Dreamcatcher, 11/22/63, Insomnia, his son's NOS4A2 novel and as an easter egg in 2017's The Dark Tower adaptation. Its face pops up as a mask in Mr. Mercedes, while The Tommyknockers' Tommy Jacklin claims he spots a "clown with silver dollar eyes" lurking in the sewers while passing through Derry, but he assumes his eyes were just playing tricks on him.

18 THEORY: PENNYWISE EXISTS IN STRANGER THINGS

Bob from Stranger Things

The Duffer brothers have made no secret of the strong influence King had on Stranger Things, the hit Netflix show about a group of kids protecting their small town from paranormal evil with the help of a psychic girl. But fans think there could be a more concrete link than just aesthetic and thematic similarities.

The link between Strangers Things and IT is made by Bob Newby. While trying to help Will Byers cope with his trauma, Bob recounts a childhood story of being plagued in his dreams by a clown called Mr. Baldo who tried to give him a balloon. Bob also just so happens to have been brought up in Maine where IT takes place. Coincidence? Not according to the Duffer brothers.

17 TRUTH: PENNYWISE IS FEMALE (AND PREGNANT)

IT Pennywise Spider

If you've read the novel IT, you'll be familiar with the unexpected form that Pennywise takes towards the story's climax. (For those who haven't and are patiently waiting for IT: Chapter Two, you might want to skip ahead if you want to stay spoiler-free.) Pennywise's clown guise is its favorite scare suit but not its real one.

The closest we ever get to seeing what it really looks like is when the Losers finally have the monster on the ropes, and it reveals its "true" Earthly form: a giant spider. But, not just any giant spider. "Oh, dear Jesus," Audra Denbrough says. "IT is female." Female and pregnant. Is this just another illusion? Is there a Mr. Pennywise somewhere? We may never know.

16 THEORY: PENNYWISE'S BALLOONS CONTAIN SOULS

Why is Pennywise so obsessed with the idea of "floating?" And what's with the all the balloons? You could chalk it up to its affinity with clowns, who famously hand out the children's party accessories, but perhaps the balloons actually have an association that's closer to home for the creature. Pennywise's actual form exists in a place called the "deadlights."

Though not its realm of origin, this non-physical dimension is said to contain orange balls of light that seem to float forever. It's been speculated that the deadlights are actually a sea of "balloons," each using the soul of a child slain by Pennywise like helium, with spider legs for strings -- a nod to Pennywise's "true" physical form on Earth.

15 TRUTH: PENNYWISE'S REAL FORM

Pennywise IT

The one thing we're always desperate to know about shape-shifting creatures is what they really look like. From horror movie icons to creepy clowns to the face of your best friend, Pennywise is a master of disguise. Its giant spider body is commonly thought of as its real form, but this is just the closest approximation of it on Earth.

Pennywise comes from a non-physical dimension, meaning its actual body is more abstract than our brains can compute. Bill Denbrough christens this zone as the "deadlights" when he catches a rare glimpse of it -- a sight that usually drives people to madness. He reports seeing an orange-lit "endless, crawling hairy creature" in it, which is likely what IT really is.

14 THEORY: STEPHEN KING IS BILL DENBROUGH

stephen king

Authors often put themselves into their own works, whether intentionally or not. Stephen King fans have spotted clear avatars for King himself pop up in about half of his considerable body of work, and IT is no exception. Reddit user brownsnake84 not only believes King used the Losers Club's Bill Denbrough to funnel himself into but that King is Bill.

The poster reckons King spent years of his adult life trying to recover the traumatizing memories of what happened to him in Maine because of the effect that shapeshifters have on adults. After reconnecting with Ben Hanscom and Mike Hanlon, he eventually pieced enough together to write the novel IT as a warning about Pennywise's possible return in 2038.

13 TRUTH: PENNYWISE'S DISGUISES

IT Pennywise

In the 2017 film, we see Pennywise hop into some strange skins to induce maximum scares from its victims: a creepy painting of a woman, a diseased vagrant and the burnt remains of Mike Hanlon's family. In the book, Pennywise's disguise counter -- including its resting clown form -- hits 24.

Some of these include frightening real-life figures from the kids' lives and some are figures from mid-century pop culture that clearly got under their skin -- Dracula, the Mummy, the shark from Jaws and the titular werewolf from I Was A Teenage Werewolf. Pennywise also becomes a horde of piranhas, winged leeches, an 8 foot-tall dog and -- even weirder -- a statue of Paul Bunyan.

12 THEORY: PENNYWISE HAS A CORALINE COUNTERPART

Bedlam smiles in a sinister fashion during Coraline

Two celebrated authors, one shared evil? In Neil Gaiman's Coraline, a demonic creature called the Beldam poses as Coraline's "other mother," lulling her into a false sense of domestic bliss after seeing that the girl is unsatisfied with her real home life. She preys on lonely children, fattening up their souls with superficial kindness until they're ready to be eaten.

In her true form, the Beldam is really a female spidery monster, which fans have noticed is a lot like Pennywise's final form in IT. The Other World could be the deadlights; Oregon is a good stand-in for Maine and both of them target children for sustenance. Could the Beldam be a long-lost cousin of Pennywise using alternative hunting methods?

11 TRUTH: PENNYWISE'S OLDEST ENEMY...

The-Dark-tower-It-Reference

...is a giant turtle. No, really. If you're not clued up on the mythology of King's shared universe then brace yourself for some bizarre home truths. Pennywise is one of the oldest and most powerful beings in the King-verse, matched almost exclusively by a creature as weird as it is: a huge, ancient turtle called Maturin, who features most prominently in The Dark Tower series.

Maturin is one of 12 Beam Guardians that hold up the Tower. His existence predates Earth's entire universe. His sweet nature makes him Pennywise's natural enemy, and though Maturin never directly interferes, he lends the Losers his strength to fight his old adversary -- an act that later costs him his life at Pennywise's hands.

10 THEORY: PENNYWISE'S FATE IS TIED TO DERRY

IT Derry

Like any horror icon, Pennywise is damn hard to permanently put down -- even with the aid of a cosmic turtle and a bunch of psychic kids. Given it's a primordial evil that resides in an incorporeal dimension, maybe we shouldn't be surprised that the clown just keeps coming back for more. One theorist thinks the creature's continual salvation is tied to the town of Derry.

"Its connection to Derry is noted, with the entire town under Its control and the town almost being destroyed when It supposedly dies. Keyword: almost. Derry is a reflection of its soul and serves to help ground its physical form, so while its body was seemingly killed, its true self beyond reality escaped death and remained intact."

9 TRUTH: PENNYWISE'S WEAKNESSES

Pennywise reaching out to grab a kid

If a god-like being like Maturin is no match for Pennywise, how the heck can anything be enough to even graze it? Well, Pennywise may be anything but mortal but that doesn't mean it can't bleed. When it uses a physical vessel in our dimension, that vessel can be attacked and hurt like any other physical thing -- you just have to be brave enough to do it.

Crucially, Pennywise must "obey the laws" of its form. So, when using the body of a werewolf, Pennywise becomes vulnerable to silver. This also proves Pennywise is generally weak to "belief," like the belief that vampires burn in sunlight, or the Losers' belief in the strength of their friendship to finally take it down.

8 THEORY: PENNYWISE'S INFLUENCE IN 11/22/63

11/22/63 tells the story of a time traveler who tries to prevent one of the most infamous moments in US history from happening: the assassination of President John F. Kennedy. King's alternate history novel shares an explicit link to IT as lead character Jake Epping journeys to Derry in 1958 and meets Beverly Marsh and Richie Tozier.

Reddit user SDBred619 thinks that given King's novels all happen in the same universe, and the close proximity in timing, the "dark presence" Jake says he felt in Derry could have only been Pennywise's. They also note the similarity between Beverly's final confrontation with her father and the grim fate one of Jake's student's families, speculating that Pennywise influenced both events.

7 TRUTH: PENNYWISE CAN EAT ANYTHING

Pennywise is famous for chowing down -- almost exclusively -- on human children, and it loves to play with its food. In terms of plot logic, the clown's preferred slow burn hunting method helps the Losers Club survive long enough to defeat it, and the idea of something relishing the thought of tracking you down as well eating you adds to the terror.

The novel attributes Pennywise's preference for scaring its prey to taste: "fear floods the body and salts the meat," making spooked kids a delicacy but not a dietary requirement. Really, Pennywise's status as an "Eater of Worlds" means it can consume just about anything it wants to -- eating and eating until a planet is picked clean.

6 THEORY: PENNYWISE WILL CAUSE THE APOCALYPSE

Pennywise IT

Pennywise reappears in intervals of 27 years, gorging for about a year before going back into hibernation. On Earth, it's been doing this since about 1740 after crash-landing on our planet, starting with a three-year rampage that claimed the lives of hundreds of settlers when Derry was founded. Some theorists believe that each time Pennywise returns, it gets stronger and stronger.

Some even believed that the prophecized Mayan apocalypse in 2012 would be Pennywise's doing, as by then it would have grown into a parasite of globally devastating proportions. As 2012 has come and gone apocalypse-free, it's safe to say that Pennywise has missed that deadline, but the idea that it could one day raze the Earth still holds weight.

5 TRUTH: PENNYWISE IS A DOPPELGANGER

Stephen King Song of Susannah

A Lovecraftian universe like King's incorporates every wacky sci-fi trope you'd expect: galactic voids, elemental beings, ancient evils, and parallel universe doppelgangers. In King's world, doppelgangers are referred to as "Twinners." King used this concept to explain the creative liberties that the TV adaptation of Under The Dome took.

He also made The Dark Tower series' Sheemis Ruiz a Twinner of Bryan Smith -- the real-world man who hit King with his van in 2000 and strangely passed away on the author's birthday. In Song of Susannah, the penultimate Dark Tower installment, ex-succubus Mia talks about six supreme demon elementals, one of which includes a spider that's thought to be Pennywise's Twinner.

4 THEORY: PENNYWISE IS A WRINKLE IN TIME'S VILLAIN

A Wrinkle In Time IT

As well as joining the dots between IT and The Shining, YouTube's Film Theorists have also made a pretty convincing link between the fanged clown and a non-King novel: Madeline L'Engle's A Wrinkle In Time. The similarities between L'Engle's 1962 children's fantasy book and King's body of work haven't gone unnoticed.

Other than the obvious detail that AWIT's main villain is referred to as "IT," the video essay also points out that both IT and AWIT's Big Bads are intergalactic shapeshifters who can manipulate minds, use colorful, child-pleasing disguises and are powerless against expressions of love. Considering other striking parallels between the mechanics of King and L'Engle's worlds, the theory concludes the two could mirror each other in the same multiverse.

3 TRUTH: PENNYWISE'S POWERS

Pennywise IT

Some of Pennywise's abilities are obvious and others are more carefully concealed. It's clear that the sewer-dwelling monster can change into any form (sometimes even combining them at once) conjure up illusions; travel around unseen and/or instantly; read and control minds and is pretty thick-skinned. You can give it a headache after a good whack to the head but dispatching it permanently is near impossible.

Pennywise's more underrated powers include psionics -- soul-stealing and pouring out destructive psychic energy; chlorokinesis -- draining the life out of plants as it does in its sickly vagrant form and minor omnipotence. Pennywise was born billions of years ago and its god-like powers are matched only by Maturin and beaten only by the multiverse's fictional creator. (Not King.)

2 THEORY: PENNYWISE AND THE LOSERS

IT Losers Club

Strap yourself in for this one! Remember the whole pregnant spider thing that is Pennywise's "true" form in Earth's physical realm? The question of how or why a being as ancient and -- until that point -- presumed s*xless is a pressing one for fans. One of the wildest and yet oddly compelling answers is that Pennywise's immaculate conception happened through the Losers.

Not physically (thank god...) but psychically via the controversial hook-up that the preteens engage in before the final showdown in the novel. "11-year-old kids don't just decide [that] under normal circumstances," the theorist argues. "Fighting It prematurely aged them [...] and the idea that It used its connection to sap their virility to spread more of itself makes a lot of sense."

1 TRUTH: PENNYWISE'S CREATION

The Dark Tower

Where on earth does a child-eating demi-god without a physical body come from? The answer is definitely nowhere near Earth. Pennywise is equaled in strength and age only by its bitter enemy, Maturin the giant space Turtle, Beam guardian of the Dark Tower. Further fuelling the confusion over Pennywise's gender, Maturin refers to it as his "brother."

This familial connection exists because the pair share technically shares the same parent: "The Other," which is likely the alter ego of the God of King's world: Gan. The Dark Tower's Roland suspects that the Tower itself is a physical manifestation of Gan; an omnipotent being responsible for just about everything that exists and, crucially, the only thing that outranks Pennywise.