SAN DIEGO – Not everybody adores evil clown Pennywise. But the cast members of "It: Chapter Two" love the very committed co-star underneath all that freaky makeup.

As the crazy-eyed clown that returns to Derry, Maine, every 27 years, Bill Skarsgard haunted a young version of the Losers’ Club in the first 2017 hit “It." He returns to terrify their adult selves nearly three decades later in “Chapter Two” (in theaters Friday).

“Each of the Losers have an encounter with It, whether it's Pennywise or an incarnation,” director Andy Muschietti tells USA TODAY.

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In 1989, the kids made oaths to return to Derry if the evil entity ever came back, and they’re still traumatized many years later, like Andy Bean’s character Stanley Uris. His “relationships with Pennywise and memories are very clear, very distinct and it was all very disturbing, nightmarish and horrible,” Bean says.

One of the most important scenes for Jessica Chastain’s character, Beverly Marsh, is an emotional faceoff with Pennywise. “He throws back at her how men have treated her, and she has to overcome it in order to be able to move forward,” Chastain says.

Isaiah Mustafa teases a moment where his Mike Hanlon encounters a constricted Pennywise, and what impressed him was how much Skarsgard put into his performance. “He gave everything. It was very eye-opening for me just to see how awesome he was at playing this character.”

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In his signature costume, Skarsgard strikes a “really imposing” figure and is amazing to watch, says Jay Ryan, who plays the adult Ben Hanscom. He loves the way Skarsgard can keep one eye forward and move the other all around: “That's one of his party tricks.”

Muschietti acknowledges there’s a tense “atmosphere” when Pennywise is on the set. Skarsgard would warm up and get into character in a secluded tent where he'd have final touches done on his makeup and insane getup. Sometimes a loud evil laugh would come out of there, “and everybody would shut up.”

There was a palpable sense of anticipation during those days, says Bill Hader, who stars as grown-up Richie Tozier. “You'd be standing there and then you would see the (filmmakers) go, ‘OK, Bill's ready.’ It was like an animal on set, like you're working with a bear. ‘OK, guys, we're bringing the bear in.’ ”

But his fellow actors respected how physically arduous being Pennywise was. “When we had him, (the) clock is ticking and we have to get as much out of him as possible,” says James McAvoy, who plays Bill Denbrough.

“Aside from being a really good actor, he's cool as a cucumber and no complaints in being able to ride through the discomfort of how long it takes to get into and out of (his costume),” adds James Ransone, who plays adult Eddie Kaspbrak.

Hader cops to grumbling sometimes. But "after I worked with Bill for one day, we were all like, ‘All right, I should really check myself.' "

There were days when the other actors would be filming reaction shots, and although he didn’t have to, Skarsgard would come in just to do the creepy Pennywise line readings offscreen. “And within the first sentence, we were like, 'I'm really glad he did that,’ ” McAvoy says.

And when he was done, “we would all thank him,” Hader adds. “We're like ... you just made all of us better actors by showing up.”