This was supposed to be the final episode of the series (not counting the Jimmy/Timmy Power Hour crossovers), until Season 6 was ordered and the show was revived. Instead, "Fancy Schmancy" ended up being the final episode.
Cosmo and Wanda are not seen in their normal forms in this episode. They are disguised as a pencil and a pen respectively for the majority of the episode, and were shown in their cat forms in one other scene.
This is the last episode until "Jerk of All Trades" to only feature Timmy, Cosmo, and Wanda as main characters.
Van Helsing - When Principal Waxelplax presents the new teacher, it appears as an animated version of Van Helsing. Also, he's searching for monsters at the school. Coincidentally, a child version of Dracula appears.
Sanjay's voice attracting cats whenever he throws it around ("Yep! It's true-lu-lu-lu-lu-lu-lu!")
Cosmo making horrifying words longer.
Someone getting a gold star.
Mr. Turner's car disappeared when all the cars jumped and followed Timmy.
Principal Waxelplax comes in and tells the class how Mr. Crocker broke his "failing hand." But, after Ms. Sunshine throws the F rocks out the window, you here Mr. Crocker shout, "I'm still down here!" It is impossible for the doctors to do an x-ray while Mr. Crocker was in the well. Also, if he were to have gotten out of the well and gotten an x-ray, he wouldn't have gone back into the well.
Mr. Crocker's arm couldn't have been broken because he would've had a cast, instead he had a sling. Also, at the end, Mr. Crocker offers Timmy a gold star and can bend his arm like a normal arm.
When Mr. Crocker comes back to being the normal teacher, he shows no sign of having a broken arm. Although, Timmy could have simply wished his arm was better, but that is highly unlikely as Crocker would have instantly gotten suspicious of this. However if Timmy did wish his arm was better, he probably also altered Crocker's memory to insure he would find nothing strange of his instantly fixed arm.
Ms. Doombringer places a giant butterfly net over Timmy's school. However, when Timmy is exiting Crocker's lair, the net is gone. Also, it is impossible for him to go through the disappearing net.
Ms. Doombringer intalls metal fences to block the door. But Timmy and his friends escape through the door without any problem.
When Timmy fell into the Crocker Cave, he should have been hurt, but he just got up and moved the mattress. Why did he do that anyway and why was the mattress not in its correct place? It could be possible Timmy is durable to some extent as he has been hurt in some other ways but didn't get that much harm inflicted on him.
When Cosmo was sneezing, nothing happened. He apparently doesn't have the fairy flu in this episode. But in The Fairy Flu, when Cosmo sneezed, something happens such as sneezing them to space, sneezes to change Vicky to a frog, and sneezes to change Tootie's head into something dangerous.