For more than 15 years, Clancy Brown has voiced the grouchy crustacean Mr. Krabs on the animated series, “SpongeBob SquarePants.”

When plans emerged for a second film spinoff, following 2004’s “The SpongeBob SquarePants Movie,” the actor didn’t have any hesitation about getting back in the sound booth, though he did have skepticism.

“Honestly, what goes through my mind when they decide to make a movie of an 11-minute cartoon is like, ‘How are they going to do that?’ ” he tells The Post. “Even ‘The Simpsons’ or ‘Bugs Bunny’…That world just exists so well within that [TV] time frame, and that’s what our brains are wired for. But they did a really good job with this one.”

“The SpongeBob Movie: Sponge Out of Water” hits theaters Friday, and follows the yellow fellow and his pals as they emerge from the sea and enter into live-action territory (via 3-D CGI) to recover the stolen secret recipe for Krabby Patties — SpongeBob’s favorite food.

Along for the ride, of course, is the hefty, penny-pinching creator of Krabby Patties, SpongeBob’s longtime boss, Mr. Krabs, who happens to have a bit in common with the man who voices him.

“I might be approaching his physical [shape] as I get older,” Brown, 56, cracks.

Ohio-born Brown got his start in acting in the mid-1980s, memorably starring in the fantasy flick “Highlander.” But things kicked into high gear when he began taking voice roles for animated series, such as “Gargoyles” and “The Mighty Ducks.”

Luckily, a renaissance was emerging in the animation industry, and the roles flooded in for Brown, who is now married with two kids.

Aside from “SpongeBob,” he is closely associated with his work in animated DC Comics series — fans recognize him from voicing the villainous Lex Luthor in various projects.

Last year, that DC connection led to a recurring role on the new hit live-action superhero series “The Flash,” in which DC fans finally can see Brown in the flesh.

“I’m really enjoying that,” he says. “I don’t think it’s quite as controlling in DC as Marvel is. Marvel has a real tight hold of their properties [with] the powerful studio guys there. DC, I think, is a little looser and a little more fun.”

Brown is hard at work filming the Coen brothers’ “Hail, Caesar!” alongside George Clooney and Scarlett Johansson. But he’ll always come back to Mr. Krabs.

“I wouldn’t mind doing it until the end of time,” Brown says with a laugh. “There’s just no corollary in live-action work — television or films or anything — to playing a miserly crab on the bottom of the ocean. I mean, goodness!”

So how about revealing the secret formula for that Krabby Patty that drives SpongeBob wild?

“I’m not going to tell you, I’d have to kill you,” he says. “Actually, if I told you, I would never play Mr. Krabs again. I wouldn’t have to kill you — we would both be killed.”

Where do I know Clancy Brown from?

Everyone’s favorite pineapple inhabitant returns Friday in “The SpongeBob Movie: Sponge Out of Water.” Joining in the fun with SpongeBob, of course, is his miserly boss, Mr. Krabs.

What fans of the hit animated series may not realize is that the voice of Mr. Krabs, Clancy Brown, is a pretty prolific guy. Here’s where you may know him from.

‘Highlander’ (1986)

Brown’s breakthrough screen role was in the sci-fi cult favorite as the immortal Kurgan.

‘Earth 2’ (1994 – 1995)

He starred in the short-lived NBC series about a space exploration group searching for a cure to a fatal disease.

‘Gargoyles’ (1994 – 1996)

Early on in his voice acting career, Brown played several characters on the animated series, including Wolf and Hakon.

‘The Shawshank Redemption’ (1994)

As Captain Byron Hadley, Brown was part of the cast that led the film to seven Oscar nominations.

Numerous DC animated series (1996 – present)

Brown has voiced roles for the comic book brand’s animated shows countless times. He’s perhaps best known for playing the iconic villain Lex Luthor.

‘Mighty Ducks’ (1996 – 1997)

One of the Ducks’ adversaries was Siege, also voiced by Brown.

‘SpongeBob Squarepants’ (1999 – present)

Mr. Krabs first appeared in 1999, and Brown has been voicing him ever since.

‘Jackie Chan Adventures’ (2000 – 2005)

Captain Black, Jackie’s friend, was voiced by Brown.

‘Teenage Mutant Ninja Turtles’ (2012 – present)

The current Nickelodeon iteration of the reptiles features Brown as the villainous Rahzar

‘The Flash’ (2014 – present)

Sticking to his DC roots, Brown crossed over to a DC live-action series for the first time on CW’s “The Flash” as General Wade Eiling.