When any novel is going to be adapted into a feature length movie, it's almost guaranteed that some things are going to have to be changed. Some of this is due to time constraints (The Harry Potter movies would each be at least 3 hours a pop otherwise), while some elements just don't work as well on film as they would in a book. The latter is the case for IT, the highly anticipated adaptation of Stephen King's classic novel. The book hints at the idea of a vast cosmic mythology at work behind-the-scenes, but the movie will largely be ignoring that specific detail.
I was never too crazy about the mythology, but it is mentioned, and the turtle appears, as a Lego. It's a Lego turtle. It's a presence that's there in the key moments of the story. Especially when--- there's a moment where they're all together--- well, you'll see in the movie. I won't spoil you.
Director Andres Muschietti is helming the IT film adaptation, and while he's clearly embracing the horror of the book, certain other elements will have to be avoided. The film has already cut a particularly uncomfortable orgy scene, but Muschetti also won't be diving into the deeper mythology of IT. Muschetti told Collider that he was never a big fan of that plot detail of the book and won't be steering very hard into it for the live action version. This is mostly reflected in the absence of the Turtle. It would be a spoiler to those still hoping to finish the IT novel before the movie to reveal exactly what the Turtle is, so I'll just say that it ties into a deeper mythology behind It and that it has a presence in a few other of Stephen King's books (like the upcoming Dark Tower).
While Stephen King fans may be disappointed to hear the Turtle won't play a big role, it isn't something that's incredibly vital to the story. It's just an element that enriches the deep history of the supernatural parts, but if the movie wants to just be a horror story about a shape-shifting clown trying to eat a bunch of kids then that works too! Keep it simple. That doesn't mean that the Turtle won't be present in easter egg form though. The above mentioned LEGO can be briefly seen in the new trailer, and Andres Muschetti further teased more easter eggs to Collider.
It's a bit of an Easter egg. There's a scene where they're screaming and it's the first time the group comes together, and they're in a quarry and they're having fun, and you think there's something under the water... Bill--- I think Richie says "Who the fuck was that?" And Bill goes under the water and says 'It's a turtle.' We don't see it. And that's it.
That sounds good enough! Fans of the book can always just have their own head canon that the Turtle is still doing its thing in the periphery. IT keeps looking better and better, and I'm excited to how it's all going to come together. The movie is set to give you horrible nightmares on September 8, 2017.