Stephen King was way ahead of the curve when it came to clowns being the fucking terrifying monsters.
His sprawling (i.e. 1,138 pages!) 1986 novel IT chronicles the haunting of a group of friends from Derry, Maine by a manipulative, shapeshifting creature from beyond named Pennywise, who appears to the children as a wacky clown. And by wacky I mean creepy as all hell. Even on the page, Pennywise reads as Freddy Krueger by way of Bozo, and the first cinematic incarnation of the book, a 1990 two-part miniseries, became instantly iconic for nothing more than matching Tim Curry's evil grin with the red-nosed reaper of souls. Even a Google image search of Pennywise is enough to keep you up for the night.
Which is why Hollywood was keen to revive the adaptation as a feature length film. From Mama director Andrés Muschietti, this September's IT lifts from the first half of King's novel, following the young pack of friends known as "The Losers' Club" as they battle for their lives against Pennywise. As the first full-length trailer for the movie demonstrates, Muschietti is willing to do whatever it takes to get his version of the clown (played by 26-yaer-old Bill Skarsgård) stuck in your brain.