NEW YORK >> The breakout star of the summer moviegoing season isn’t a dinosaur, an Avenger or anyone aboard the Millennium Falcon. It’s a giggling pipsqueak in diapers.

“The Incredibles 2,” which last weekend set a new box-office record for animated films with $182.7 million in ticket sales, has been a coming out party for Jack-Jack, the seemingly all-powerful baby of the Parr family. Jack’s superhero powers were teased in 2004’s original, but, they were, crucially, kept out of view from his family members.

“The Incredibles 2,” though, is a runaway-train of Jack-Jack revelations. Just as infants half-consciously babble and wobble as they feel out their abilities, Jack-Jack’s unknowingly careens through his Swiss Army Knife of superpowers. A sneeze rockets him through the roof. Anger turns him into a purple devil. His crib can be escaped by simply walking through the bars.

(Those are just some of his powers. Estimates run as high as 17.)

The New York Times called him “the burbling, gurgling cherry on this confection.”

The Wall Street Journal hypothesized that Jack-Jack could be “as valuable a commodity for (Disney’s Pixar) as the Minions who stole the show in Universal’s ‘Despicable Me.’”

Jack-Jack fever has struck. And that’s been especially enjoyable for the real-life Jack-Jack, who was just a toddler when the first “Incredibles” was hitting theaters. Pixar animator Tony Fucile, who supervised animation and designed the characters for both “Incredibles” movies, used recordings of his infant son, Eli, to craft Jack-Jack’s voice.

Eli Fucile, now 16, is in the strange position of starring in one of the year’s biggest movies, while being unable to recall ever participating in it.

“I didn’t really understand it when I was younger. But as time went by, I realized: ‘Wow, I was actually in a pretty good movie,’” said Eli in his first interview. “It’s been nice to see all the feedback. I guess everyone loves Jack-Jack.”

Eli was 10-months old when his father, a regular collaborator with “Incredibles” director Brad Bird, was animating the first film. Tony’s newborn son, also gifted with an especially spherical head, resembled the baby they were in the midst of creating.

“We actually designed the character first and then the actual being came into existence,” said Tony. “I was talking to Brad and I said, ‘You know, Eli’s been doing some wacky sounds. It’s this sort of pre-verbal jag he goes on. He’ll wake up and he just goes. It’s laughter and sort of all over the place. Kind of like Stromboli (of ‘Pinocchio’).”

Bird, intrigued, got Tony an audio recorder and boom mic, and instructed him how to use it.

“He was very persnickety about the sound,” said Tony. “He said, ‘Cover up the windows with blankets and then point the mic at his mouth.’ When (Eli) woke up from a nap, he was in that mood, ready to riff. So my wife and I started following him around the house for about an hour and a half.”

Those recordings have remained like the Dead Sea Scrolls of Jack-Jack. They supplied the basis of the character’s voice for the first “Incredibles,” a 2005 Jack-Jack short and even the new sequel. Though Eli is the top credited voice actor, there’s some composite work. To voice the purple monster version of Jack-Jack, Bird used recordings of one of his sons, the now 13-year-old Nick (who presumably was a less well-behaved baby).

Fucile assumed they’d need another infant for the sequel, but editor Stephen Shaeffer was able to unearth still more from the original tape.

“I wish we had done more recording,” said Tony. “I didn’t expect that it would last.”

Eli estimates he lost the ability to make Jack-Jack sounds when he was 9 or 10 years-old.

“Once the voice cracked, that was the end of that,” said Tony. “Yeah, unfortunately,” echoed Eli.

“The Incredibles 2” takes places just a few months after the original film, but the passage of time has had curious effects for the cast. Dash, the middle child of the superhero family, was previously voiced by Spencer Fox. Ten-year-old Huck Milner was brought in this time. At the “Incredibles 2” premiere, Milner was confused meeting the voice of his fictional younger brother.

“He was like, ‘Wait, you’re older than me,’” recalled Eli, chuckling. “I was like, ‘Yeah, buddy.’”

For Tony, the years meant a second chance to animate Jack-Jack, to improve his facial gestures and give him some powers that weren’t technically possible 14 years ago. As the development went on, Jack-Jack got more and more prominent.

“There was no real limit to what could be done,” said Tony. “It was one of those things where it was: Why can’t he do this?”

And for Eli, it’s his first chance to revel in being Jack-Jack. Even if not everybody thinks it’s him.

“All my friends didn’t believe it at first,” said Eli. “They’re like: ‘What? You did a baby voice?”