After half a century of mysteries, Scooby snacks and unmasking ghouls, We look back at the canine crime-stopper's enduring appeal.
Be honest, when you were a kid, there was at least one Scooby-Doo monster that scared the living daylights out of you.
Maybe it was the theatrically sinister demon puppeteer, the pterodactyl ghost that appeared without warning at the window, or - we shudder to think of it now - the evil hypnotic clown.
The first ever episode, What A Night For Knight, set the tone nice and early. As the camera pans down over a full moon to the sound of screeching violins, a truck driver fails to notice that the suit of armour he's transporting has come alive, and is creeping up on him with a pair of glowing yellow eyes.
It's really quite spine-tingling, and the following half-hour lays down the eternal Scooby-Doo template - chase sequences, Rube Goldberg traps, the required dose of Mystery Machine, and an entirely predictable unmasking at the end.
For many years, it was rinse and repeat - to near-universal acclaim. Here, to celebrate 50 years of Scooby, we take a look back at the canine crime-stopper's enduring appeal...
Looking back with adult eyes, perhaps the show's greatest achievement was creating iconic characters - still one of the go-to group fancy dress costumes today - out of cardboard cut-out stereotypes.
Fred was a hunky blonde everyman who'd probably been on his college football team, and whose heroic lack of personality became a running joke in later seasons. Daphne was a distressed damsel with an hourglass figure, nearly as scared of the monsters as she was of breaking a nail, while Velma was intelligent, and therefore bespectacled and frumpy.
Best by far was Shaggy - an open-and-shut stoner with a grim little goatee, and clothes that were probably once a shade of cream. One of the first to popularise putting 'like' in every sentence, he had less success with his other buzzword, 'zoinks'. We're not going to ask what Scooby snacks are infused with, but they seem to be really moreish.
The most multi-faceted character is probably the titular Scooby, whose over-the-top gluttony and theatrical cowardice perfectly suit his role as a comedic, talking dog. He's apparently a Great Dane, though with bowed legs, double chin and sloping spine you wouldn't know it to look at him.
The many faces of Scoob
It's understandable that execs valued continuity, because when the pilot aired in 1969, the show had already been though enough iterations to make Terry Gilliam wince.
From the studios of Hanna-Barbera - nicknamed 'the General Motors of Animation' - early drafts detailed a show called 'The Mysteries Five', following a crime-solving rock band and their bongo-playing hound, 'Too Much'. Daphne was 'Kelly', Velma was 'Linda', and Shaggy went by the less-than-snappy acronym 'WW'.
For the first full pitch to CBS, the show was renamed 'Who's S-S-Scared?', and focused more on supernatural spookiness than wink-at-the-camera comedy, but it was immediately branded too frightening.
A main piece of the puzzle fell into place with the name Scooby-Doo - surely the only cartoon character to be named after a Frank Sinatra lyric. CBS executive Fred Silverman was inspired by Sinatra's scat singing at the end of Strangers In The Night, in which the Chairman of the Board improv-ed the line "doo-be-doo-be-doo".
Following another rebrand - to the light-hearted capers of Scooby-Doo, Where Are You? - the show was accepted, and was an instant success. With the exception of the ill-fated New Scooby-Doo Movies, there followed the show's golden years. Every dog has its decade, and the 1970s were Scooby's.
The rise and fall of Scrappy-Doo
It's genuinely possible that Scrappy-Doo is the most hated cartoon character in history, but in 1979, he almost certainly saved the show.
Amid falling ratings the show-runners were demanding change, and, on pain of cancellation, the writers cautiously crafted a new character to slot in beside their main cast. "If this doesn't work," Barbera said, "Scooby is dead."
On debut, Scrappy was a hit. Lauded by critics and audiences, the pugnacious pup was the perfect foil to Shaggy and Scooby's cowardice, and injected some much-needed energy into a programme that was running out of storylines.
Buoyed by his success, executives promptly axed Daphne, Velma and Fred, and dropped all their responsibilities onto Scrappy's diminutive shoulders.
Hindsight is 20/20, but even so, it was a dreadful move. Suddenly the star of a show that was not his own, Scrappy's fast-talking, cheeky-chappie act became steadily more irritating, even as the writers experimented with episodes without even Shaggy and Scooby.
Realising their mistake far too late, the show brought back Daphne in 1983, but ratings were irreversibly waning. Scrappy's last cartoon aired in 1988, but it was the increasing internet access of the Nineties and Noughties that allowed fans to get together, and realise how much they all hated him.
A regular punchline in recent shows - "we all promised we would never speak of him again" - Scrappy had a fitting sign-off as the Big Bad in the first Scooby-Doo movie. Portrayed as a petty, narcissistic little Napoleon, it was perhaps a tacit admission from the studio that maybe, at some point, they had goofed.
To borrow a quote from a very different franchise, Scrappy should have died a hero, but lived long enough to see himself become the villain. "Scrappy did exactly what he was supposed to," wrote creator-in-chief Mark Evanier, "he got Scooby-Doo renewed for another season."
This time, they're real
Scrappy's introduction was the first big tonal change - the second saw the advent of real, bona fide monsters. Take Scooby's first full-length feature, Scooby-Doo On Zombie Island, a horror-comedy with hordes of zombies, frankly terrifying were-cats, and settlers being devoured by alligators.
The film was well received by critics, but not necessarily by all the fans. The charm of Scooby-Doo was always wrapped up in colour and quirk, and feelings of genuine threat were mitigated by the final reveal that the monster was - drum roll please - a man in a suit.
When the zombies are real, the whole tone shifts. "Jinkies! Looks like the satanic cult revived the decomposing flesh with ancient voodoo, and then sustained their spell with human sacrifice. What a kooky mystery!"
By the time we got to Mystery Incorporated in the 2010s, the gang were facing down inter-dimensional demons called Annunaki, whose objective was nothing less that the destruction of space and time.
Scooby-Doo will keep creating new content, but his legacy is already assured, and it's worth noting that he enjoyed a surge of renewed interest in the 1990s purely from a steady stream of reruns.
That's the wonder of children's television - to each new generation, Scooby too is new.