The film, based on the iconic Stephen King novel of the same name, was released last Friday and has already raked in a huge amount at the box office.
The movie managed a hefty $117 million in the US - way up on its initial estimates of $50-60 million.
Skarsgard, who plays Pennywise, has been particularly praised for his performance.
On the clown’s menacing attack, he told Rolling Stone: "I don't know if you've seen kids run like this, but they move their arms way too fast, and it looks really, really funny.
“And I just loved the way my brother ran as a kid. It was just out of sync.
“So I incorporated that into the character, and you get this really explosive effect.
“It's really unsettling when it happens."
It is thought that a sequel - It: Chapter Two - is officially in the works.