Yogi Bear, Huckleberry Hound and Snagglepuss once ruled as crown princes of Saturday-morning TV. Now they are simply hoping to hold court among a legion of young streamers who watch video at any time they choose.

The cartoon characters are stand-outs from the Hanna-Barbera animation studio, which in the last half of last century accounted for the bulk of animated programing shown each Saturday morning on ABC, NBC and CBS. Creations ranged from the memorable (“The Jetsons,” “Scooby Doo”) to the decidedly less so (“Squiddly Diddy,” “The Hair Bear Bunch”). On Thursday, dozens of Hanna-Barbera characters are being set loose anew in “Jellystone!,” a new HBO Max series that seeks to revive several generations of animated favorites for an audience that may not know them all that well.

“This was definitely the biggest challenge I have had,” says C.H. Greenblatt, creator and executive producer of the new series, in an interview. “We were basically making ‘The Simpsons,’ season five, right out of the gate,” he adds, making a reference to the famous cartoon series that developed an entire town of characters to surround the offbeat family at the show’s center.

The Hanna-Barbera troupe was crafted for an era when most Americans watched the same thing at the same time. Under the auspices of Bill Hanna and Joseph Barbera, the studio made shows that looked a lot like what people watched during TV’s primetime.  “The Flintstones” aped “The Honeymooners.” Animal protagonists like Quick Draw McGraw, Augie Doggie and Magilla Gorilla starred in what were essentially animated sitcoms. And there were plenty of crime procedurals, like “Goober and the Ghost Chasers” and “Clue Club,’ packed with “meddling kids” who saved the day.

“The Flintstones” was a hit, says Joe Garner, author of “It’s Saturday Morning!: Celebrating the Golden Era of Cartoons 1960s-1990s,” largely “because it mimicked so much of what was already very successful,” as did the other Hanna-Barbera properties.

And yet, Warner hasn’t made use of most of its Hanna-Barbera library, which its Turner acquired in 1991, in years. Yes, the company recently released a movie based on “Scooby-Doo” and has tested projects involving Yogi Bear and Top Cat, but projects featuring the rest of the crew have been few and far between. Cartoon Network once gained traction with bizarre series that turned  Hanna-Barbera’s Space Ghost character into a talk-show host, and another superhero, Birdman, into an attorney. But teammates like Hardy Har Har, Inch High, Private Eye, the Funky Phantom and Hong Kong Phooey have been left on the shelf.

The rise of streaming may just save them all.

Media companies have grown ravenous for any property that has heritage and some sort of connection to consumers, particularly kids, whose entertainment consumption habits can spur parents to open their wallets for a new streaming subscription. Under those circumstances, the Hanna-Barbera library has suddenly been transformed from a musty repository for once-popular properties to a treasure chest of potential concepts that have a connection to several generations of wage-earning streaming customers. In April, WarnerMedia announced it was giving Hanna-Barbera more of a spotlight, rechristening its European Cartoon Network studio operations with the old moniker.

“It wasn’t until streaming showed up that our opportunities sort of expanded,” says Sam Register, president of Warner Bros. Animation and Cartoon Network Studios.

Other Warner animated properties have been retooled. The studio has a new version of “Animaniacs” on Hulu and has revived its landmark “Looney Tunes” shorts with Bugs Bunny and Daffy Duck. When it came to Hanna-Barbera, however, executives had largely been stuck in a “Scooby vortex,” says Register, focused largely on that cartoon canine and his mystery-solving companions.

They called in Greenblatt to see if he might do a shorts program for Hanna-Barbera. The producer is known for “Chowder,” a cartoon series about an apprentice cook whose appetite often serve as a recipe for making trouble. After some development work that involved investigating potential avenues for Hanna-Barbera characters, Greenblatt thought he might fare better if he put many of the studio’s animal creations into a single odd town and let them bounce off each other.

There is precedent. Hanna-Barbera fielded a team in “Yogi’s Gang,” a 1973 animated ABC series in which Yogi, Wally Gator, Atom Ant, Pixie, Dixie, Mr. Jinks and others grappled with villains who embodied social issues like bigotry or greed. And the characters found other challenges in 1977’s “Laff-A-Lympics,” an ABC series that had three teams of Hanna-Barbera durables competing in various contests. Grape Ape, Speed Buggy and The Great Fondoo were among the participants.

If “Jellystone” were to work in 2021, however, many changes had to be made. The characters were developed in an era when animation was more rudimentary and could only show so many positions and expressions. Some figures, including a few meant to emulate Native Americans, were taken out of the list of candidates for the show because their depictions were offensive. And if producers hewed too close to the way the figures acted in past decades, they’d never be able to make them relevant for modern audiences. The older Hanna-Barbera designs “flatten out a bit,” says Benjamin Lee, the art director on “Jellystone.” New designs make the characters look like more modern animated figures with “more action and expression,” he says.

Keeping the characters as is would have been great for older generations who recalled them from youth, but not for the new viewers the company hopes to attract. “There was a certain look and sound to the old stuff, which I love, and people who love Hanna-Barbera connect to it, but it creates a feeling of nostalgia you can’t compete with,” Greenblatt says. “You have to drop it and let it break and then pick it up and see what’s left and make something new.”

There were other big challenges to meet. Most of the Hanna-Barbera characters are male.

“How can you have dozens and dozens of characters and none of them are women?” asks Greenblatt. “It doesn’t make much sense.” To be certain, Captain Caveman worked with a trio of “Teen Angels” (Brenda, Dee Dee and Taffy) and Magilla Gorilla had a young female friend named Ogee, but those weren’t the most prominent roles. “It was always the sidekicks,” says Greenblatt.

No longer. Cindy Bear, a milquetoast female foil for Yogi in the old days, has been elevated in the pantheon. In decades past, she had little backstory. Today. she has a career as a doctor (as do Yogi and Boo-Boo), but she is on her game and as much a part of the proceedings as her male contemporaries. “I’ve been trying to keep her silly, sweet and endearing as much as I can,” says Grace Helbig, the actor who gives Cindy voice, but that belies the fact that the character is sharp — perhaps more so than her contemporaries.

Other moves are more radical. Some of the male characters  — among them Jabberjaw, Yakky Doodle and Squiddly Diddly – are now female. “We had to gender swap some of these,” said Greenblatt. “It’s just not fair to the audience,” he says,  to keep female characters as they were in the original shows.

One decision along these lines changed a familiar relationship: Augie Doggie, who regularly hung out with his proud Doggie Daddy, is now female, creating a father-and-daughter relationship that Greenblatt believes will be just as winning as the previous one. “He’s an overbearing helicopter dad,” the creator explains. “It becomes really funny to make her this sweet, loving, sheltered child.”

The characters have the capacity to show more depth. “The Hanna-Barbera library is extremely wide but extremely shallow for most of the characters. There are a few who go into the deep end — the Flintstones, the Jetsons, people who had more time to explore more of the characters.” says Greenblatt. “But a lot of them are really just catchphrases and voices and great designs. There was a lot of room to really explore who they are without making change for the sake of change.”

Huckleberry Hound, the elder-stateman character who was portrayed as a sort of folksy underachiever who wins out by sheer luck, is now the mayor of Jellystone. Magilla Gorilla, who is one of the few characters to wear more than a tie or a hat, is the proprietor of a clothing store. The Funky Phantom is now a former professional wrestler. Snagglepuss, who used to tell viewers about his plans to exit a scene, is the local celebrity.

And if viewers aren’t careful, they might just get a little inspiration. “Even if the show might just seem like completely surface-y and silly, there are some complex themes being interwoven,” says Helbig. “There’s a lot of stuff about community building” and getting along in a specific environment, no matter how many different characters live there. “All of the characters in this absurd town spend episodes building and destroying it. But they do it together.”

If you can’t find your Hanna-Barbera favorite, keep looking. Producers intend to mix in obscure figures over the course of the show, and will even drop in some of the heroes, like Jonny Quest and Hadji.  If a second season is granted, Greenblatt would love to arrange cameos by the Jetsons or even less familiar characters, like the cast of “Devlin,” a Hanna-Barbera serial about a daredevil who embraced the lifestyle of an Evel Knievel.

After all, in the streaming world, any animated concept with a little history has a new chance for life. “I’ll keep pushing for as much as I can,” says Greenblatt. “And as many as I can.”