It: 11 Easter Eggs You Probably Missed
10. Eddie’s Christine T-Shirt
Christine, the tale of a supernaturally possessed car, is one of Stephen King's most oddball stories, but references to it seem to crop up in a lot of his work.
The eponymous 1958 Plymouth Fury appeared in toy form in the recent Dark Tower adaptation you're trying to forget about, and in It, the vehicle features in thread form.
During that scene where the Losers meet to study the map of Derry's sewers, Eddie Kasprak’s T-shirt depicts a murderous car with big pointy teeth, which is no doubt a nod to Christine.
It plays it fast and loose with this reference, since Christine doesn't have big pointy teeth, but she did have glowing green eyes, so close enough.