* AccidentalInnuendo: The episode "Monsters Are Real" has Ickis freak out because a human photographs him. What's odd is that he describes it as a human "flashing" him, which takes on rather risque implications when taken out of context.
* CargoShip: Ickis falls for a Judy doll in the episode "Blind Love, Monster Love"
* EarWorm: "Ickis and Fungus, he's not a virus"
** "We're the cutest monsters you've ever seen, we are joyful and jolly and never mean!"
* FridgeHorror: Throughout the series, there are a few references to the "Era of Disbelief", a period sometime in the forties when humans stopped believing in monsters. If one tracks all the hints, one can work out that this period lasted from 1943-1945 - the period of UsefulNotes/WorldWarII where the Allies managed to turn back the Axis Powers. Since the show later establishes that bad times for humans are good times for monsters, the implication is that the monsters gorged themselves during the Great Depression and the Holocaust, nearly disappeared as the world economy recovered and the Axis fell, and then recovered thanks to the Red Scare and the Cold War.
* HilariousInHindsight: People who've seen this cartoon along with ''Monsters Inc.'' might get the idea that both the cartoon and the film have similar plot settings since both involve monsters who need to scare in order to collect energy for their society. Come ''Monsters University'', the setting is even more similar to the cartoon as it involves monsters going to school in order to learn how to scare. Mike and Sulley even fill out roles similar to two of the three main characters of the cartoon. A super studious and hardworking student that relies heavily on books, and another student who is generally lazy but pressured with living up to the family legacy of being the best scarers.
** Thanks to ''WesternAnimation/CowAndChicken'', this show is not the only one that has Creator/CharlieAdler voicing a red monster with mood swings...nor is it the first time he's voiced a [[WesternAnimation/TinyToonAdventures rabbit-looking character who goes to school]].
** A bespectacled character on a Nickelodeon show, who is determined to prove that a supernatural race is real, despite other people thinking he's crazy. [[WesternAnimation/InvaderZim Will we ever see this again?]] [[WesternAnimation/TheFairlyOddparents Yes]] (twice, in fact).
** In ''"Smile and Say Oblina"'', Oblina gets hooked up with a metal device wired to her jaws with corkscrews and a timer on it. [[Film/SawI Fast forward to 2004, and we have a movie featuring a torture device that looks similar to that]].
* UglyCute: Ickis. Actually, most of the monsters had this tendency, but in Ickis' case his appearance made it more difficult for him to be taken seriously. At least until [[OneWingedAngel he goes bigger...]]
** Ickis seem to be this ''in universe'', given Oblina's comment on a photo of him.
--> Oblina "This really does not do him justice, he's much uglier."
** Vlorina in ''"The Great Race"'' is adorably {{Moe}} and this.