Also mentioned earlier in this article, IT is one of those scary movies too classic not to mention twice. I mean, a clown that lures kids into rain gutters? Classic. That rising feeling of anxiety throughout the film is emphasized with little appearances of Pennywise throughout the whole film in random spots. Sometimes they are so subtle that you need to have really been paying attention.
You can see an example of this when the Losers help Ben after his altercation with Henry Bowers. There is a mural on the wall behind them of the Bradly Gang shootout, infamous for the time adults remembering seen Pennywise’s character. At first glance, the mural appears to be normal, but at a second glance, the audience can see Pennywise show up behind the car wheel, coincidentally right behind Ben.