Although Its most infamous face is that of Pennywise the Dancing Clown, A.K.A. Bob Gray, It's not just the clown. In fact, It can be whatever It wants to be, whether that's a giant bird, a living Paul Bunyan statue, a teenage werewolf, a swarm of flying leeches.... The list goes on. And yet, when It isn't in a disguise, It is somehow more horrifying than when It changes shape.

The writer's woman was now with It, alive yet not alive — her mind had been utterly destroyed by her first sight of It as It really was, with all of Its little masks and glamours thrown aside — and all of the glamours were only mirrors, of course, throwing back at the terrified viewer the worst thing in his or her own mind, heliographing images as a mirror may bounce a reflection of the sun into a wide unsuspecting eye and stun it to blindness.

There's a very good reason that It can look like anything, though, and that's because...

Poor Stan Uris. Although he was able to help the Losers Club defeat It the first time they faced It, when he gets the call telling him that Derry is under threat once more, he decides that suicide is better than going back to fight the monster again.

When his wife finds him, she discovers that Stan has made his reasons for suicide abundantly clear:

He had dipped his right forefinger in his own blood and had written a single word on the blue tiles above the tub, written it in two huge, staggering letters. A zig-zagging bloody fingermark fell away from the second letter of this word — his finger had made that mark, she saw, as his hand fell into the tub, where it now floated. She thought Stanley must have made that mark — his final impression on the world — as he lost consciousness. It seemed to cry out at her: IT.

Although the novel tells readers that Stan was always a sensitive kid, that doesn't make his sudden death any less tragic, nor does it cushion the blow of this chilling realization — It is so scary that some people, like Stan, would rather end their own lives than have to experience It again.

One of the reasons It loves to kill so much is that It knows exactly how to manipulate and frighten each of Its victims. First, It must lure them in, and then It must terrify them in order to "salt the meat," before finally killing and eating them. Its ability to shapeshift is what gives It the power to feed on new victims every 27 years.

It had always fed well on children. Many adults could be used without knowing they had been used, and It had even fed on a few of the older ones over the years — adults had their own terrors, and their glands could be tapped, opened so that all the chemicals of fear flooded the body and salted the meat. But their fears were mostly too complex. The fears of children were simpler and usually more powerful. The fears of children could often be summoned up in a single face... and if bait were needed, why, what child did not love a clown?

To anyone who is already afraid of clowns, I apologize for introducing that last sentence into your life.

It may be Stephen King's scariest villain, but It is also my favorite villain, ever. Mainly because It delights in killing things. Seriously, when It kills Adrian Mellon in the novel, Adrian's boyfriend, Don Hagarty, tells police that he saw the clown hug him to death, smiling as the poor guy's ribs were breaking.

Ade's right arm was stuck stiffly out behind the clown's head, and the clown's face was indeed in Ade's right armpit, but it was not biting: it was smiling. Hagarty could see it looking out from beneath Ade's arm and smiling.

The clown's arms tightened, and Hagarty heard ribs splinter.

Talk about brutal.

It wakes up to feed every 27 years or so, during which time Derry experiences an outbreak of grisly murders, arsons, accidents, and disappearances. But after It goes back to sleep, everyone in Derry forgets what happened, and no one notices when the cycle repeats itself. That's by design, of course, as Losers Club member Mike Hanlon explains to the group:

"It left Its mark on us. It worked Its will on us, just as It has worked Its will on this whole town, day in and day out, even during those long periods when It is asleep or hibernating or whatever It does between Its more... lively periods."

That's why the Losers designated Mike as the one to remember. His job is to watch over Derry, and to call the Losers back to face off against It whenever It returns. But even Mike has trouble remembering the awful things that happen in Derry:

"I can remember everything up until August 15th 1958 with almost perfect clarity. But from then until September 4th or so, when school was called in again, everything is a total blank. It isn't murky or hazy; it is just completely gone. With one exception: I seem to remember Bill screaming about something called the deadlights."

Its ability to make people forget about Its existence is frightening enough, but that fear only grows when you realize that It may not be the only one of Its kind out there.

When the Losers face off against It in 1985, Ben and Richie discover something new in the dark web of tunnels that It calls home — Its innumerable eggs. Naturally, they try to destroy as many of them as possible:

[Ben] went to the next egg and repeated the process in the last of the dying light. Everything was repeated: the brittle snap, the squelch of liquid, the final coup de grâce. The next. The next. The next.... The eggs were pallid stones in the dark. As he reached each one he struck a light from the matchbook and broke it open. In each case he was able to follow the course of the dazed spiderling and crush it before the light flickered out. He had no idea how he was going to proceed if his matches gave out before he had crushed the last of the eggs and killed each one's unspeakable cargo.

Although It ruminates a lot on being alone, in the brief interludes King gives readers in Its consciousness, it's possible that 1985 was not the first time It had ever laid eggs. It's also entirely possible that Ben missed an egg or two, and that a few little Itlings survived to haunt Derry in perpetuity.

Perhaps the most unnerving thing about It is that It isn't from Earth, or even from outer space, but from someplace beyond all that. The deadlights It uses to hurt Audra are a path into the macroverse — Its name for the place It comes from. Stan gets an idea as to Its homeworld in 1958:

[A]fter awhile you think maybe there's a whole other universe down there, a universe where a square moon rises in the sky, and the stars laugh in cold voices, and some of the triangles have four sides, and some have five, and some of them have five raised to the fifth power of sides. In this universe there might grow roses which sing. Everything leads to everything, he would have told them if he could.

How are you supposed to fight something that isn't even designed to exist in the same world as you? The thought itself — and of Itself — is horrifying.