While the gang are traveling to a diner to meet one of Scooby and Shaggy's friends, the Mystery Machine gets stolen by a trio of mud monsters. Upon arrival, Fred, Daphne, and Velma are kidnapped by the monsters, leaving Shaggy, Scooby, and the "friend" in question, rock star Axl Rose, to hunt down the villains.
This episode includes examples of the following tropes:
- Blind Without 'Em: Velma loses her glasses during the mud monster attack and one of the monsters grabs her.
- Damsel in Distress: Daphne, Velma, and the waitress get kidnapped by the mud monsters (though the waitress' "kidnapping" was only for show, because she is one of the mud monsters).
- Dine and Dash: A trio of teenagers try to leave the diner without paying, saying that they have to save the money for Las Vegas. Axl puts a stop to it and makes them tip the waitress, much to their irritation.
- Distressed Dude: Fred and one of the male diner staff both get kidnapped by the mud monsters (though in the diner staff's case, it was a hoax, because he and his friends were the mud monsters).
- Gratuitous Spanish: The waitress calls Shaggy "mijo" when he orders a slice of every pie.
- Improvised Weapon: Axl throws pie tins to keep the college customers from dining and dashing.
- Interclass Friendship: Shaggy and Scooby are friends with rock superstar Axl Rose, and like Shaggy and Chris Paul, they also have a secret handshake. Velma even asks how on earth that happened. It turns out that they ran into Axl in a diner, where they shared a pie. Given that Axl travels and eats in diners a lot (and Shaggy and Scooby just like eating), they became bonded over their quest to find the best pies in America.
- Luck-Based Search Technique: While Shaggy and Scooby are attempting to juggle, they drop most of the oranges. One bounces across the room and into a secret passage, giving them a break in the case.
- My Life Flashed Before My Eyes: When he, Scooby, and Axl swing across a deep pit, Shaggy says that he just saw all three of their lives flash before his eyes. He declares that Axl's life is awesome.
- Mythology Gag: While reporting the Mystery Machine's theft to emergency services, Fred lists the van's "birth year" as 1969, the year Scooby-Doo, Where Are You! came out.
- Running Gag:
- Shaggy and Scooby noting some kind of similarity between Axl and one of the others and suggesting that he should hang out with them...if they ever find them again.
- Axl doing something random in the middle of a bad situation and saying it helps him think.
- Shout-Out: Some Latin over a door in the abandoned city says, "Abandon all hope, ye who enter here."
- Skewed Priorities: When the mud men steal the van, Fred complains about them messing up the interior.
- Sommelier Speak: Played for Laughs. Shaggy, Scooby, and Axl apply words like "forward-taste", "opening", "finish" and "aftertaste" while tasting every pie in the diner.
- This Is No Time for Knitting: Axl starts juggling soon after the mud men kidnap the other members of the gang, causing Shaggy to ask if they shouldn't be looking for the others instead. Axl apologizes and says that juggling helps him think. Shaggy and Scooby try to help and their clumsiness reveals a secret passage.
- Trap Is the Only Option: Shaggy isn't too happy when they accidentally find a spooky secret passage. Scooby isn't very pleased with the prospect either, but he points out that they have to find their friends.
