The closing credits of Scoob! offer a wealth of Hanna-Barbera Easter eggs, with nods to other shows besides Scooby Doo. While this montage is fun for fans of classic cartoons to pick through, they also offer some insight into what films viewers may see in the same shared universe of Scoob! in the future.

Founded in 1957 by Tom and Jerry creators William Hanna and Joseph Barbera, Hanna-Barbera Productions was one of the dominant forces in American animation in the late 20th century. Hanna-Barbera was responsible for producing some of the most popular cartoons of all time, including Scooby-Doo, Yogi Bear and The Smurfs. The company was sold to Ted Turner in 1991 and their library of classic cartoons was used to establish Cartoon Network, before all of their properties were absorbed into Warner Bros. Animation in 2001.

Related: What Song Is In The SCOOB Trailer?

The idea of a shared universe made up of all the various Hanna-Barbera properties seems a bit far-fetched on paper, but the company started crossing their characters over with series like Laff-A-Lympics and Yogi's Space Race long before such things were commonplace even in the world of comic books. As such, there's good reason to believe that Scoob's closing credits could be teasing future stories in the same setting, similar to Spider-Man: Into The Spider-Verse. The following is every Hanna-Barbera Easter egg in Scoob!'s closing credits.  

Atom Ant

Atom Ant

Not to be confused with the singer of "Goody Two-Shoes," Adam Ant, Atom Ant was the co-star of The Atom Ant/Secret Squirrel Show in 1965. An animal superhero in the same vein as Mighty Mouse, Atom Ant used his powers of flight, super-strength and invulnerability to face such villains as Ferocious Flea and the mad scientist Professor Von Gimmick. He appears in Scoob!, wearing a new costume that appears to be heavily inspired by Ant-Man, as one of the new superheroes recruited for Blue Falcon's Falcon Force team.

Jabberjaw

Jabberjaw

Reportedly created to cash-in on the popularity of Jaws, Jabberjaw was introduced to the world in 1976 as the "most futuristic shark you ever saw." He somehow possessed the power to walk upright and breathe out of water. This would seem to make him the reverse-Aquaman of the new Falcon Force, which is fitting as they both get "no respect."

The Great Grape Ape

The Great Grape Ape

Though most people were scared senseless by his size, the 40-foot tall purple gorilla The Great Grape Ape was a gentle soul — despite often causing a good deal of property damage by accident in the 1975 series he shared with Tom and Jerry. Curiously, he is wearing a mask when he appears in Scoob! as one of the new recruits for Falcon Force, suggesting there's a chance he might be mistaken for other 40-foot tall purple gorillas with a green bow-tie and ball-cap.

Captain Caveman

Captain Caveman

Captain Caveman was the star of Captain Caveman and the Teen Angels, which was created to capitalize on the popularity of Charlie's Angels in 1977. Like Captain America, he was trapped in a block of ice for many years, before being revived to continue his war on evil. Armed with a utility club containing various Stone Age gadgets to complement his super-strength, Captain Caveman was later established as being a superhero in the same reality as The Flintstones. Scoob! offers up a major retcon of this history, however, with Captain Caveman appearing as the guardian of the third Skull of Cerberus on Mystery Island; an island similar to the Savage Land in Marvel Comics where dinosaurs and cavemen still live. Based on the closing-credits sequence, Captain Caveman made his way to the surface world and remained there to join Falcon Force.

Related: Scoob! Voice Cast & Character Guide

Dr. Benton Quest

Jonny Quest Cast

The cartoon Jonny Quest holds the distinction of being the first adventure series Hanna-Barbera produced. Premiering on ABC in 1964, the series centered around the titular boy explorer, his adopted brother Hadji, their scientist father Dr. Benton Quest and their bodyguard, Race Bannon. Jonny Quest is so iconic that it served as the basis for the long-running Adult Swim show The Venture BrosDr. Quest's lab is the background of one section of the post-credits sequence of Scoob! and Dr. Quest himself appears showing a blueprint to Fred, Daphne and Velma while Scooby Doo and Shaggy roast hot dogs over one of his Bunsen burners.

Rosie The Robot

The Jetsons and Rosie the Robot

Despite patriarch George Jetson being ludicrously underpaid by his boss, Mr. Spacely, The Jetsons still managed to afford a robot maid named Rosie. This may have been because Rosie was an older model of robot and considered obsolete and old-fashioned by the standards of their age. It as never established just how old Rosie is, but the montage at the end of Scoob! suggests that Dr. Benton Quest was her designer.

Frankenstein Jr.

Frankenstein Jr. from Hanna-Barbera

A giant 30-foot tall robot resembling the classic film portrayal of Frankenstein's monster, Frankenstein Jr. was the creation of Buzz Conroy Jr. and his father, Dr. Buzz Conroy. Whenever supervillains, aliens or giant monsters threatened the Earth, Buzz could summon Frankenstein Jr. though a special ring to come flying and save the day. A hologram of Frankenstein Jr. can be seen in the background of Dr. Quest's lab, suggesting he may have consulted with Dr. Conroy or may have asked him for advice on building Rosie.

Wacky Races

Wacky Races

First airing in 1968 and likely inspired by the 1965 film The Great Race, Wacky Races centered upon the misadventures of a collection of screwball drag racers and their unlikely vehicles. Dick Dastardly and Muttley were the villains of the show, though they would go on to be the main bad guys in other Hanna-Barbera productions; most notably their own series, Dastardly & Muttley In Their Flying Machines. A sketch of Dick Dastardly and Muttley's classic designs can be seen on the wall of Dr. Quest's lab. Later on in the closing credits of Scoob!, blueprints of the various Wacky Racer cars can be seen on the wall of Dick Dastardly's prison cell, as Muttley arrives in a giant mobile drill to break him out of prison. Could this be a hint as to Dick Dastardly's next sinister scheme?

More: How Classic Scooby-Doo Cartoons Influenced A 1970s Slasher Movie