Stephen’s King IT may be heading to cinemas for the first time this fall, but Pennywise has already had a recent outing on the silver screen thanks to The Dark Tower. The IT Easter egg was first seen in the second trailer of Nikolaj Arcel's film as Jake Chambers (Tom Taylor) stumbles across an old, abandoned theme park after entering Mid-World. Fans of the book and the '90s TV series will know that Pennywise the clown is It’s favourite form, and the name is clearly seen on the derelict construction, with a clown hand holding three balloons. So how did It end up in The Dark Tower movie?
Stephen King fans are fully aware of the shared universe of his novels, with various characters popping up frequently in books other than their own. The Dark Tower series is actually the glue that holds all the King narratives together, because of the role the titular tower plays. The Dark Tower is the centre of all creation, and the space-time continuum, and was created by Gan, King's equivalent to God. The Tower can only be entered via End-World, one of three sections of Mid-World, and is supported by six beams that on each end has portals to other worlds. These twelve portals are manned by animal-like guardians (these don't appear in the film) and allow characters like Jake to travel from his world, Keystone Earth, into Mid-World.
The new world he enters is a barren wasteland with only tattered remnants of the former technologically advanced civilization, known as Imperium, left behind. This world was a parallel to the United States and occupied by a people called “Old Ones” who wore similar clothing, drove similar cars and designed architecture similar to that seen in the parallel Earth worlds of It's Derry and Jake's New York. Imperium may well have had a theme park and a Pennywise attraction itself, which was inevitably destroyed after these ancient people’s civil war left Mid-World a radioactive mess, and that’s why Jake stumbles across it in the movie. He isn’t from the same parallel world as the one depicted in IT, as the Derry, Maine "Mainstream Universe" is a separate one to his Keystone Earth world, however, there are still similarities between the two. The house on Niebold Street visited by members of the Losers' Club in IT shares a similar description to the wallpaper found in the Dutch Hill mansion, and the Asimov robot, Stuttering Bill, encountered by Susannah and Roland in one of The Dark Tower books, shares the same nickname as Bill Denbrough, the older brother Pennywise's unfortunate victim Georgie Denbrough.
The demonic entity also wields a power called Deadlights, an energy form used by the Crimson King, a major enemy of Roland Deschain, who is hell-bent on destroying The Dark Tower so that he can recreate the universe in his image and rule it. In the book Insomnia, it’s revealed that the Crimson King is a shape-shifter that takes the form of the thing that scares you most. Pennywise practices the same sort of fear-inducing shape-shifting to attack the children/adults of the Losers’ Club, which means they could well be connected. As Den of Geek points out, Penywise is from the Macroverse:
"Which is like Todash Darkness - a sort of nothingness that exists between alternate dimensions in the Kingverse where all the really awful creatures come from. Think H.P. Lovecraft's Great Old Ones. Although it's never stated that The Macroverse is the same thing as Todash Darkness, they sound like the same awful place. King might've just missed a retcon."
The Crimson King is also linked to Walter, A.K.A. The Man in Black (played by Matthew McConaughey), who is the main villain in The Dark Tower. Walter is actually a servant of The Crimson King in the books, with the ability to shape-shift too, and in the film he has the same goals as his master.
Similarly, Pennywise and Dandelo - a villain from The Dark Tower series also known as Joe Collins - share the same sort of power, and many readers actually thought they were the same character. Both creatures feed on the emotions of their victims - the former through fear and the latter through laughter. King ended that sort of speculation by confirming that they are most likely the same sort of Todash monster, and there’s even evidence to suggest that Dandelo is an offspring of Pennywise. It was revealed at the end of IT that the creature laid eggs under his home in Derry and one of these eggs could have hatched and gone through the portal to Empathica where Dandelo is from.
Another connection between The Dark Tower series and IT is the Turtle, Maturin, a guardian of one of the beams and sworn enemy of Pennywise. The aged turtle is more a spectator of the events in IT, but does help young Bill Denbrough during the ritual of the Chüd in 1958 to briefly defeat the demonic monster. IT director, Andy Muschietti, has said there will be references to Maturin in the form of a Lego piece as well as later in the film, but that doesn't mean we can expect a shared It/The Dark Tower universe.
The TV series, starring Tim Curry as the titular clown, did not include any references to the Turtle, and as Muschietti "wasn't too crazy about [Maturin's] mythology," IT probably won't use it in any meaningful way either. This could be because it would open up a wider, more complex narrative linking to King's multiverses rather than allowing it to be a tight, stand-alone franchise. The IT being released this year is part one of the story, focusing on the younger versions of The Losers' Club and set in the 1980s rather than the 1950s, with part two centring on the adults in present day. Bill Skarsgård is taking on the titular role in Muschietti's film, but he didn't make an appearance in Arcel's film as some fans had hoped. So any reference to The Dark Tower book series in the new IT may simply function as an Easter egg, just like Pennywise's circus attraction did in The Dark Tower movie.
However, just because there doesn't seem to be plans by Muschietti to create a shared universe within his IT duology, it doesn't mean The Dark Tower franchise will do the same. There are references to numerous King books in the film - including The Shining, Christine an Misery - and as there may be more films to come, despite the poor critical reception, they may become more than just Easter eggs and actually part of the narrative.