These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Gordy also qualifies, as he was elevated from a recurring role in Season 1 to a starring role in Seasons 2 and 3.
Family-Unfriendly Aesop: The Class Clown episode. While it is true that being amusing can lighten the tension in a School Environment, the episode encourage the viewer to clown around, even if it results in you getting in trouble.
Fridge Horror: In Guide to: Vampires, Werewolves, Ghosts, and Monsters, Moze is a ghost, which is fine at first, until you realize this means she died in this universe. Good thing it was All Just a Dream.
Special Effect Failure: The show frequently uses puppets and unconvicing People in Rubber Suits to portray various animals, and sometimes rather obvious dummies representing characters doing painful stunts. It seems that this is largely done on purpose, considering the cartoony nature of the show to begin with.
This is actually invoked in one episode where Moze thought she'd knocked out two of Coconut Head's teeth. The "teeth" are obviously pieces of white breath mints that have been cut to resemble teeth. Since audiences were used to the terrible effects, the audience just assumed it was his teeth. Then it was revealed that it really was breath mints in-universe as well.
Suspiciously Similar Song: The first chords of the tune that plays when Ned is explaining his tips to the audience sound a lot like the main riff of "I Can't Explain" by The Who.