Though he's had a few supporting roles over the last few years, Bill Skarsgård is making his big debut in director Andy Muschietti's feature film adaptation of It as the titular sewer-dwelling demon. With It, Muschietti puts a new spin on one of the most terrifying horror classics of all time.

Based on Stephen King's iconic novel of the same name, the story follows a demonic shapeshifter whose favorite persona is that of Pennywise the Dancing Clown, a creepy clown who lurks in sewers and shadows to prey on the fear (and bodies) of young children. But Skarsgård's Pennywise is an entirely original take on the iconic character.

"He brought madness to the character," Muschietti told MTV News at a press day for the film last month. "He brought unpredictability. These are two traits of the character that I wanted to bring to this version."

The director gave Skarsgård the freedom to experiment and bring Pennywise to life in any way he saw fit. But they both agreed that Pennywise needed to be a "more edgy and more layered character with stranger behavior than people expect." According to Muschietti, this unpredictability is the root of the film's horror — and to Skarsgård's "fearless" performance.

Skarsgård's take on the character is more erratic and infantile than that of his onscreen predecessor. (Not that anyone should compare the two; they're completely different visions.) He also brings a dynamic theatricality to Pennywise that fans of the King novel will instantly recognize.

"The way he moves is so unique and so different," actor Sophia Lillis said. "It is really scary."

So scary, in fact, that some of the young actors might have developed a mild case of coulrophobia, or fear of clowns, since production wrapped. "Sorry clown union," Finn Wolfhard joked.

It hits theaters on September 8, so try not to get lost in any sewers until then.