Warning: MILD SPOILERS for IT Chapter Two
IT Chapter Two surprised fans by showing Pennywise the Dancing Clown (Bill Skarsgård) transform into an unexpected form: a giant spider. However, IT still didn't quite take the shape described in Stephen King's novel or the 1990 IT miniseries. Pennywise's spider-form in IT Chapter Two seemed more like a compromise between what's in the book and what would create the most effective scares for today's movie audiences.
Richie Tozier (Bill Hader).
When the Losers Club descend into Pennywise's lair deep in the caverns beneath Derry, however, Stephen King's IT. In the 1990 TV movie, Pennywise turning into a giant spider was a laughable disappointment, but this was also due to the limited special effects of the era. The TV Pennywise's giant spider was done with stop-motion and, frankly, it looked ridiculous and not scary.
IT Chapter Two explores Pennywise's origin, and it's to that IT's spider form is linked. Director Andy Muschietti's film shows that IT crashed on Earth in a meteor from outer space millions of years ago and claimed the territory that would one day become Derry, Maine as its evil stomping grounds. In King's novel, IT is actually an ancient evil force hailing from its home dimension, which is called the Deadlights (depicted as the three balls of light in the film that can possess people, turn their eyes white, and give them glimpses of horror and death). In the book, young Bill Denbrough (Jaeden Lieberher) glimpsed IT's true form in the Deadlights for a moment and he described it as an endless, crawling, hairy creature made of orange light - the giant spider shape is merely an approximation of IT's native shape that humans can understand.
To be fair, Pennywise's half-clown/half-spider form is lightyears ahead of the giant spider in the TV movie, and it made for a strikingly scary and violent enemy in IT Chapter 2 for the Losers to fight in the climax. As a giant spider-clown, the film was able to utilize Bill Skarsgård's performance as Pennywise to the utmost so IT could taunt the Losers as IT tried to kill them. Since all of the Losers' animosity towards Pennywise was derived from IT's clown form, retaining him as a clown in his spider-shape helped make Losers fighting IT - and ultimately winning - feel much more personal and cathartic. Still, many fans didn't expect to Pennywise's giant spider form in IT Chapter Two and, though it was weird to see, Pennywise as a clown/spider was a solid compromise that made for an exciting finale.
