"And yet some rationality remained, even until the end: as the Creature hooked its claws into the soft meat of his neck, as his carotid artery let go in a warm and painless gout that splashed the thing's reptilian plating, Eddie's hands groped at the Creature's back, feeling for a zipper. They fell away only when the Creature tore his head from his shoulders with a low satisfied grunt. 

And as Eddie's picture of what It was began to fade, It began promptly to change into something else."

It, Stephen King