One of the many Dark Tower series as well as some other King novels. Others speculate that the two villains are simply of the same species. King himself has never taken the time to speak on these theories; here's what we think.
"IT" is the title character and the main antagonist in King's 1986 horror novel, IT. IT is an ancient, cosmic evil that resides in which arguably deserves a movie adaptation - and the 2001 novel, Black House. The Crimson King is the ruler of "the Red," also called "the Random" and "the Outer Dark." He can generally be described as the embodiment of evil, and is constantly attempting to destroy the Dark Tower, which keeps time and space going.
The Crimson King and Pennywise share a number of interesting similarities, which sparked a theory that they're actually the same entity. The theory details that Pennywise - or, more technically, IT - is actually the Crimson King. According to the theory, they are not merely relatives or of the same species, they are one and the same character, with Pennywise being a physical manifestation of the Crimson King. This would mean that the antagonist so many readers and viewers have come to know from the IT book and screen adaptations was, all along, the Crimson King - a true force of evil.
Why Pennywise Could (& Couldn't) Be The Crimson King
King has neither confirmed nor denied the theory that Pennywise is the Crimson King, but there's some evidence found throughout his works that s it. In the Dark Tower books - which were released from 1982-2012 - the Crimson King is referred to as "the great, scuttling spider-king," and is often described as a shapeshifting spider. This shapeshifting attribute is something that Pennywise is also capable of, and Pennywise's most natural form is actually that of a spider.
In the novel Insomnia, which centers on a man with severe insomnia who sees into alternate realities, the Crimson King appears as the late mother of Ralph, the protagonist, and then shape shifts into the form of Ralph's deepest fear. This ability to understand a person's deepest, darkest fear is another ability of Pennywise's. In fact, when the Crimson King appears to Ralph, he remarks: "I can be whatever I want. You may not know it, but shape-changing is a time-honored custom in Derry." Some fans say this merely implies that the Crimson King is aware of the events of IT that took place in Derry, but others infer that this is the Crimson King revealing what he truly is.
To continue with evidence that s the theory, the Crimson King also has ties to the Deadlights, which are Pennywise's life essence. The Deadlights are described as moving orange lights that exist in Todash Darkness, which is the dark, monster-filled void that exists in between worlds. Pennywise uses the Deadlights to mess with a person's mind, because looking at them will make one go insane. His spider form is the closest a human mind can come to seeing the deadlights without going insane. In the Dark Tower series, the Deadlights appear when the Crimson King is climbing up the tower; it's also implied that the Crimson King uses the Deadlights for his enemies, throwing them out into Todash Darkness where they go insane.
The Crimson King also has similar metaphysical properties to Pennywise. When his physical body is stuck on the upper balcony of the Tower, his metaphysical form moves around freely in the Court of the Crimson King. Pennywise, too, has a metaphysical form that resides in the Deadlights, while his physical form remains in Derry. One last piece of evidence that backs the theory that Pennywise is the Crimson King - both characters refer to themselves, at different times, as "the Eater of Worlds."
Despite all of this evidence suggesting that Pennywise is indeed the Crimson King, the argument that the two are separate beings remains. Some fans suggest that Pennywise, the Crimson King, and other similar beings throughout King's novels - like Mordred and Dandelo from the Dark Tower series, who also possess spider-like or other insect-like qualities - have the same origins. One can hypothesize that these entities all descend from the Crimson Queen - an insectile entity from the Prim who is known primarily as the Crimson King's mother - and that's why they all possess dark forces and spider-like qualities.
Pennywise/IT Could Be The Crimson King
In the end, the theory that Pennywise is actually the Crimson King is extremely plausible. It can be said that Pennywise is merely a relative of the Crimson King, with both descending from the Crimson Queen, but the evidence suggests that there's a deeper connection than that. Both characters can shape shift, access a person's deepest fears, and use the Deadlights, plus they are both often referred to as a shape-shifting spider.
The idea that Pennywise is actually a physical manifestation of the Crimson King is clearly ed. Also, this theory ends up making the events of IT much scarier. Not only was Pennywise trying to terrorize the protagonists of the story, but at the same time, he was a cosmic god also attempting to end creation. It's not clear why Stephen King has decided to remain silent on this theory concerning "the Eater of Worlds." Perhaps, as an expert in the horror genre, he knows that the mystery of IT is what makes it all the more terrifying for his readers.
