Bill Skarsgard told USA Today that he's been hard at work freaking out the new grown-up members of the Losers Club, particularly Jessica Chastain. Skarsgard said, "There was a moment in the script where Pennywise has a line and I took a little beat before I said the line and projected my voice really loudly as Pennywise. And I got her pretty good." He added, "The whole room jumped. I let them know what's coming."
On slipping back into the terrifying character, Skarsgard said, "It's a strange thing. I put in so much work to figure him out in the first one, and coming back to him now, I was surprised how much the character was already there.
In addition to rattling his co-stars nerves, Skarsgård has been working to amp up the character a little bit, or the threat of him, and explore new things that havent been explored. This is the final showdown and its going to be different.