Twenty-seven years after their first encounter with the malevolent creature IT, the Losers Club have grown up and moved away except for one of them who still lives in Derry, Maine. A devastating phone call reunites the childhood friends and when they return to their hometown they start to remember the sinister shape-shifting clown 'Pennywise' (once again played by Bill Skarsgård) that preyed on children, played on their fears and tried to kill them.

In the supernatural horror film Bill Hader plays an adult 'Richie Tozier' and Finn Wolfhard his younger counterpart, Andy Bean plays a grown up 'Stanley Uris' with Wyatt Oleff the younger boy, James McAvoy stars as an older 'Bill Denbrough' (whose brother 'Georgie' was abducted and killed years before), and Jaeden Martell in younger self and Isaiah Mustafa plays the grown up 'Mike Halon' (who remained in Derry) and Chosen Jacobs the younger version.
Sophia Lillis returns as the younger 'Beverly Marsh', whilst Jessica Chastain plays her older self, 'Eddie Kaspbrak' is played by James Ransone and the younger Jack Dylan Crazer, and Jay Ryan plays a grown up 'Ben Hanscom' and Jeremy Ray Taylor the younger boy.
You can see more of his design work with these movie costumes from The Shape of Water on display.
I don't doubt that this immediately iconic Pennywise clown costume will be popular once again at Halloween this year.