* BrokenBase: "Desperately Xeeking Xena" to an extent. On one hand it's considered the strongest segment of the otherwise unexceptional episode, but some don't care for it being the first time the series completely eschewed spooky elements despite being a horror series.
* EnsembleDarkHorse: Stretch Dude and Clobber Girl, at least to the people in charge of writing the ''Simpsons'' comics. Werewolf Flanders has also appeared in merchandise.
* FranchiseOriginalSin: Part of why "Desperately Xeeking Xena" has a BrokenBase. Despite being the first to abandon the horror genre in favor of parodying a completely different one (superhero morning cartoons), there is a HandWave in-universe as it begins in Halloween, and Bart and Lisa get their superpowers from an accident with a X-ray machine used to check candy for safety. Had following episodes stuck to the horror/Halloween theme, this might be considered an original spin that subverted expectations rather than the moment SeasonalRot took over the Treehouse series.
* HarsherInHindsight:
** A Simpson causing the death of a Flanders family member stops being funny after the episode "Alone Again, Natura-Diddly (only replace "Marge" and "Ned" with "Homer" and "Maude"), which aired only a few months later. Furthermore, at one point Moe calls up the (recently widowed) Maude in an attempt to stalk/date her. In the latter episode, after the funeral, Moe then begins to "console" Ned by telling him how hot she was and that if he had died instead, he would be all over her. This angers Ned so much, he starts ''punching Moe in the face repeatedly'' as the bartender reacts gleefully, saying for him to "send me to Maude!"
** The joke about Creator/DickClark actually being a robot who gets affected by the Y2K glitch, resulting in him melting and decaying in "Life's A Glitch, Then You Die" didn't age too well when he had a stroke in 2004 and less so after his death in 2012.
* HilariousInHindsight:
** The Collector held a phaser that was allegedly fired once to prevent Creator/WilliamShatner from making another album. Since 2004, Shatner has released eight albums.
** The show doing a MillenniumBug story in 1999 becomes this after [[Recap/TheSimpsonsS33E1TheStarOfTheBackstage "The Star of the Backstage"]] had a teenage Marge (and several other characters) involved in a production of an a [[ShowWithinAShow play]] based on the bug at around that time (ComicBookTime strikes again) before putting on a repeat of it during that episode's present day.
* TheyWastedAPerfectlyGoodPlot: "I Know What You Diddily-Iddily-Did" has been criticized for ending abruptly without ever properly explaining such plot points like why Flanders was stalking the Simpsons dressed like a fisherman or pretended to be dead for so long, leaving the whole conclusion feeling quite rushed.
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