Scooby-Doo has been around for almost 60 years. The lovable dog and his quirky gang of mystery solvers have thwarted many a monster in a mask, enchanting viewers along the way through their eccentric likeability and screwball humor. Of course, 60 years is a long time. To keep the repetition at bay, the series has done many things to mix things up.

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The Scooby-Doo creators often accomplish this through crossovers. Most of these involve celebrities, but they sometimes incorporate other fictional characters into the stories as well. Bringing in these additional franchises changes the usual group dynamic and injects a fresh bit of lore to explore. It may not always much sense, but it sure is fun — as the episodes below prove.

10 Laff-A-Lympics

Scooby-Doo in the Laff-A-Lympics

Before crossovers were a dime a dozen, this must have blown fans' minds. Dozens of Hannah-Barbera characters come together for one grand event. Divided into teams, these icons then compete in a series of Olympic games, ranging from races to wrestling to bull-riding.

Scooby's team — aptly named the "Scooby Doobies" — predictably contains several canine characters. These include Dynomutt, Hong Kong Phooey, and Scooby-Dum. What can you say? Dogs stick together. Sadly, they missed the opportunity to include Huckleberry Hound; he's over on Yogi Bear's team. Traitor.

9 All The Times The Gang Met Batman

Batman and Scooby-Doo

This is a testament to the enduring quality of both crime-fighters. Scooby and the gang have met Batman several times over the course of the franchise's lifetime. The first was back in The New Scooby-Doo Movies — a show featuring celebrity guests — where they encountered the strait-laced and somewhat cheesy Caped Crusader of the time. The next was a feature film crossover with Batman: The Brave and the Bold, a throwback to those corny Silver Age tales.

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The most recent was Scooby-Doo and Guess Who?, another celebrity guest series. Along with Wonder Woman, the gang met a more serious Dark Knight. Despite his solemn character, the script still threw in a few self-deprecating jabs at Batman's theatricality; they could only play this so straight.

8 Bravo Dooby Doo

Scooby-Doo and Mystery, Inc. in Johnny Bravo

Johnny Bravo wasn't above the odd dig at pop culture, but this still stands as one of the more random episodes. On the way to his grandma's house, the titular muscle-head gets a ride from Scooby and the gang.

What unfolds is a caper involving a ghostly gardener, a slightly cynical yet formulaic adventure right out of the '60s show. The self-absorbed Johnny is thrown into the mix and annoyed at the whole ordeal. With that setup, the humor writes itself.

7 When Urkel-Bots Go Bad!

Urkel in Scooby-Doo and Guess Who?

As the name suggests, Scooby-Doo and Guess Who? features a new guest every episode. However, these are normally celebrities like Morgan Freeman or Wanda Sykes. When Jaleel White comes on, though, he's not playing himself.

Instead, he voices his iconic character from Family Matters, Steve Urkel. As if that wasn't trippy enough, the kid has invented a robot in his likeness. He may be a dweeby dork, but he's not lacking for confidence. It's just a shame the robot has turned into an Urkel-nator.

6 Scooby-Doo! WrestleMania Mystery

Scooby-Doo and Shaggy in Wrestlemania Mystery

Tecnically, guys like John Cena, The Miz, Triple H, and AJ Lee are real people. When the gang head to WrestleMania, it just seems like a feature-length episode of one of their celebrity guest shows.

What isn't real is the plethora of of superpowers they seem to have. Every so often, the wrestlers will display some feat of inhuman strength, such as when Cena stops a two-ton boulder. They can't even do this in the games. Of course, Scooby and Shaggy are bigtime WWE fans, so they just watch in awe. Wrestling is real. Who knew?

5 Keeper Of The Reaper

Scooby-Doo, Grim, Billy, and Mandy in The Grim Adventures of Billy & Mandy

While not a full-on crossover, this appearance is no less bizarre. One of The Grim Adventures of Billy & Mandy's more popular episodes involves the titular children going to the Underworld court to decide who gets custody of their friend/slave: the Grim Reaper. Believe it or not, this isn't even the weirdest this show gets.

In a rare moment of intelligence, Billy calls a bunch of witnesses attesting to how awful Mandy is. One of these witnesses is Scooby-Doo, who recounts how she made fun of his speech. He's in a room full of hideous monsters, but he fears this little girl above all. That says something.

4 Scoob!

Scooby-Doo, Shaggy, Blue Falcon, and Dynomutt in Scoob!

Desperately chasing the current trend, this film attempted to start a cinematic universe out of the Hanna-Barbera properties. It stands to reason that Mystery, Inc. would interact with other characters under that banner as a means of preemptive cross-promotion.

Blue Falcon and Dynomutt are the main ones, but the heroes also come across guys like Captain Caveman and Dick Dastardly. Sadly, most of these only loosely resemble their original versions and are an excuse for celebrity stunt casting and cheap punchlines. As such, the appeal is lessened.

3 Scoobynatural

Scooby-Doo, Mystery, Inc., Sam, and Dean in Supernatural

After being on the air for a million years, it's a wonder that Supernatural didn't do this earlier. Monster hunter brothers Sam and Dean are minding their own business when they're suddenly sucked into a TV and land right in the middle of a Scooby-Doo episode.

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Things proceed innocently enough until a real ghost starts gruesomely killing people. Mystery, Inc. aren't ready for the blood and consequences that come with fighting real demons. Daphne's even worried about going to Hell. What did she do to deserve it? That's a mystery worth solving.

2 Straight Outta Nowhere: Scooby-Doo! Meets Courage The Cowardly Dog

Scooby-Doo, Shaggy, and Courage in Straight Outta Nowhere

The most recent crossover is perhaps the perfect one. Both of these franchises deal with 'fraidy-dogs thwarting monsters. Granted, the Mystery, Inc. members aren't nearly as oblivious as Courage's owners, but is it any wonder why the two stars hit it off so well?

Drawn together by a hypnotic sound, the two canines and their humans fumble their way through a wacky adventure, one that mixes the wholesome humor of Scooby-Doo with the demented imagination of Courage. More importantly, the plucky, pink mutt is probably among Scooby's favorite crossover companions.

1 Scooby-Doo And The Cyber Chase

Mystery, Inc. in Scooby-Doo and the Cyber Chase

The lovable dog's favorite new friend would probably be himself. When one of their buddies designs a video game around them, Scooby and the gang are zapped into said game. They eventually reach the final level, where they meet the virtual versions of themselves. That's right, it's technically a video game movie.

While this is partially an excuse to poke fun at some of their quirks, past and present, each member gets along great with his/her counterpart. They even break the normal split-up pattern and just go off with themselves. This just speaks to how well their friend designed the game. Scooby Double Doo!

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