A new ride opens up at Wonder World, called the Hurl-a-Whirl. Arthur is incredibly excited to experience this with Buster, but his excitement soon dwindles when D.W. decides she wants to take her imaginary friend, Nadine, along too. Desperate to ensure she doesn't go with them, Arthur and Buster conjure up a plan to prevent her from going, but it all ends up being for naught, with Arthur continuing to fear that D.W. will embarrass him. However, after Arthur and Buster use up all their tickets to ride the Hurl-a-Whirl, D.W. decides to lend a few of her tickets over to Arthur, with her claim being that Nadine told her it was the better option than riding. Arthur is thankful for her kindness, and decides to repay her by saying he can go on whatever ride she wants with her next...and she picks the bumper cars, which he is less than thrilled about.
D.W.'s Imaginary Friend contains examples of:
- Absurd Brand Name: A carnival ride is called the "Hurl-a-Whirl" (parody of the common Tilt-a-Whirl, with the implication that you'll throw up afterwards).
- Big Eater: During Arthur and Buster's conversation at lunch, Buster keeps asking for trades that are weighed in his favor. By the end of their conversation, he has a tray stacked full of desserts.
- Debut Queue: This is Nadine's introductory episode. The next several episodes continue to debut mainstays of the series as well.
- Early-Installment Weirdness:
- In this episode, D.W. treats Nadine as if she's just as real and existent as a real-life friend. In later episodes, Nadine only shows up when D.W. is alone, and she never brings up Nadine when she's in other company.
- The Here We Go Again! music cue is heard in the middle of this episode (when David "finds" Nadine in the trunk) instead of the end like it usually is later on, and not during a Here We Go Again! moment either (though the latter at least happens a few more times).
- Gone Horribly Right: Buster and Arthur try to prepare D.W. for the Hurl-a-Whirl by making her do "exercises" in an attempt to demonstrate that she's too young to ride it. Their first exercise (spinning her as fast as they can on a merry-go-round) actually ends up making Buster more sick than D.W., while D.W. is completely unfazed by the whole thing.
- Imagine Spot: At realizing D.W. might bring Nadine with her to Wonder World, he imagines the worst case scenario where her imaginary friend will lead others to mock him by association.
- Never Say "Die": One of the first aversions happens in this episode, when Buster hypes up the ride and says "We're gonna die!"
- Tempting Fate: Arthur decides to thank D.W. by letting him go on any ride she wants with her green tickets (these are supposedly used for the smaller rides) after he and Francine ride the Hurl-a-Whirl. Cue him getting stuck on the bumper cars.
Everyone is excited to check out the new Scare-Your-Pants-Off book, and Arthur is the first to bring it to the checkout counter much to all his friends' chagrin. He soon turns out to be terrible at keeping up with his books; when he gathers them all up though, he finds The Mysterious Hand missing from his collection. Desperate to figure out who could have taken it, he consults Binky to find out who it was. After several dead ends though, it turns out the answer was right in front of him all this time...and he must pay the price when he is unable to read the book in time for a long checkout wait list to build up.
Arthur's Lost Library Book contains examples of:
- All for Nothing: After going through all the trouble searching for the new book he thought he lost, Arthur now has to get on a long wait list after its return to actually read it.
- Cassandra Truth: Binky reveals he found Arthur's book outside and started reading it before returning it to the library. Arthur laughed at the idea that someone like Binky would read a large book. However, he soon believes him because Binky didn't even know he dropped it and, as it just happened, Arthur would laugh at him.
- Dreamworks Face: Binky pulls one when he tells Arthur the reason he doesn't even read comic strips that "if they were any good, they'd be on TV."
- Everyone Is a Suspect: Arthur goes through just about all his friends trying to figure out who "took" his book. Too bad the answer happens to be the very person he consulted to help.
- Expy: The Scare-Your-Pants-Off book series are an obvious expy of Goosebumps.
- Foreshadowing: The suspect that took Arthur's book is actually really poorly hidden. If you are the least bit familiar with how the characters look, you're probably going to instantly recognize Binky's arm picking up the book early on in the episode.
- Irony: The fact that Binky was the one who took the book in the first place, when he was the one Arthur believed would be the last possible suspect since he knew Binky didn't enjoy reading. As it turns out, Binky secretly loves to read books like the Scare-Your-Pants-Off series and, being The Bully, threatens to beat Arthur up if word gets out.
- Mickey Mousing: A brief minor one, but during Arthur's Catapult Nightmare scream, the animation of his mouth closing is in rhythm to the background music.
- Narrator All Along: D.W. turns out to be the "spooky voice" narrating the story.
- Nightmare Sequence: Arthur has a truly terrifying nightmare about being haunted by ghosts, captured by the literal long arm of the law, and punished in a barbaric manner for losing a library book (by having the books he checks out chained to a crank the librarian operates). It's so petrifying Arthur even lets out all of his usual Stock Screams, including of course his Catapult Nightmare wake-up.
