Sid and Marty Kroftt took more than twenty years to move from Saturday mornings to ones on Friday.

The kiddie-show impresarios are best known for 1970s-era programs like “Sigmund & the Sea Monsters,” “Land of the Lost,” “Far Out Space Nuts” and “H.R. Pufnstuf.” Now they are preparing to launch their first kids-focused program since the early 1990s, and adding something new to their usual mix of talking puppets and surreal settings: dogs.

When “Mutt & Stuff” debuts on Nickelodeon on Friday at 10 a.m., it will contain some of the oddball elements audiences associate with a duo that produced “The Bugaloos,” a show that ran on NBC in the early ’70s about members of a band who could don antennae and wings and fly. The new program comes with a talking fire hydrant named Melvin and a guy dressed in a large dog suit. Calvin Millan, the son of animal trainer Cesar Millan, has the starring role in a series about a school for dogs that teaches kids how to handle animals — and maybe even their own emotions and feelings. The elder Millan is also an executive producer.

What’s missing? Viewers will see none of the Kroftt’s weird villains. No Sleestaks. No Witchiepoo. No Blurp or Slurp. Instead, Nickelodeon and the Kroftts are counting on a live-action program featuring dogs with names like Zippy, Surfer Dog and Cuddles who do a constant array of tricks and poses to lure kids into sticking with a 20-episode series at a time when younger audiences have become increasingly hard to reach.

“I think kids are really smart, and kids can find what they want,” said Marty Krofft in a recent interview. He and his brother had long turned away from children’s programming, he said, to focus on other genres, but he recently thought, “Look, let me try one more kids’ show and see how good we still are. We got a bull’s-eye.”

Amid a sea of Hanna-Barbera cartoons, the Kroftts were able to stick out in the 1970s with live-action concepts that took fantastic ideas – Sea monsters! A female super hero duo! A talking flute named Freddy! – and made them seem real. Nickelodeon is banking on the program, which is aimed predominantly at preschoolers, having similar appeal in 2015. “There are a million animated shows out there and the live-action genre seems to get smaller and smaller,” said Russell Hicks, president of content development and production for Nickelodeon Group, in an interview.

Others have tested that theory as well. PBS recently launched “Odd Squad,” a live-action series featuring young kids as secret agents who use math to thwart strange anomalies. And Sprout, part of Comcast’s NBCUniversal, has placed more emphasis on its live “Sunny Side Up Show,” that has celebrities visit with an anthropomorphic chicken named Chica.

Not all of them have dogs doing tricks. Nickelodeon’s Hicks says shots of dogs driving in cars, leaping up ramps and wearing disguises are not heavily edited, and their various stunts can be quite eye-catching. “Every child wants a pet. Every parent comes and tells a story – ‘My daughter wants a pet.’ This is the first step. They can watch this and learn what it takes to be with a pet, thorough a lot of fantasy and storytelling.”

For Nickelodeon, one of the jewels of parent media conglomerate Viacom, the show represents one more attempt to harness a young audience that is quickly moving to streaming video and mobile tablets. As Hicks explains things, TV networks can respond more quickly if a live-action show becomes a success than they can with a popular cartoon, though the company is by no means abandoning its animation pipeline. A new episode of an animated series can take up to a year to produce, Hicks said, while production can resume on a live-action series in more rapid fashion.

Marty Kroftt, 78, and his brother, Sid, who Marty said  is in his “mid-eighties,” have experience juggling the demands of the format. When costs for “H.R. Pufnstuf” grew to $100,000 an episode – they were initially budgeted at $54,000, Krofft said – the brothers used money from puppet shows their company ran at amusement parks to make up the shortfall.

“Mutt and Stuff” has its fair share of the Krofft’s signature phantasmagoria. In one episode, “Stuff,” the one dog on the show who is played by an actor in a costume, takes homesick Cuddles inside a tiny dog playhouse, only to show the audience, and the mutt, that the interior is a gigantic canine playground. “Mutt and Stuff” also features two bird puppets that offer commentary on the goings-on in Calvin’s school, and often slip from their perch in hilarious fashion. Did we mention the talking fire hydrant?

More from the Kroffts may be on the way. In February, Amazon Studios stuck a development deal with the brothers to develop a pilot based on “Sigmund.” Legendary Digital Media and Fullscreen are working on a reboot of “Electra Woman and Dyna Girl,” a segment about superheroes that was part of an ABC showcase called “The Krofft Supershow.”

“We hung in,” Kroftt said.

And it doesn’t seem to be that difficult, though the brothers, like anyone else in the business these days, are subject to the demands of creating content that is being watched in radically different fashion by an audience given increased power by technology.

“A good show is great characters, likeable people and fantasy,” said Krofft. The brothers will find out if the recipe continues to endure.