Crosses the Line Twice: Hiting your sister so you can claim her baby teeth? Cruel. Repeatedly hitting your superpowered sister? Bearable if not a little bit funny. Moving onto other targets and trying to pass the tusk of a kaiju off as one of your baby teeth? Absolute gut-buster.
Fanon Discontinuity: Due to Buttercup's extremely unscrupulous behavior, most fans choose to pretend this episode never existed.
Moe: Despite Moral Decay's flaws, most can agree that Bubbles without her tooth takes her usual cuteness up to eleven with her AdorkableChildish Tooth Gap and Lisp.
Along with destroying Bubbles' chalk, some fans will never forgive Buttercup for knocking out Bubbles', and then the villains' teeth despite her Jerk with a Heart of Gold moments, despite the fact that she knocked out Bubbles’ tooth by accident and felt guilty/apologized multiple times even though Bubbles and everyone else wasn’t angry at her.
Along with "forcing" Buttercup to give up her blanket, some fans will never forgive Blossom and Bubbles for their abusive, hypocritical solution, despite them being loving sisters to Buttercup normally.
Fans will never let The Professor's No Sympathy reaction to Buttercup having her teeth knocked out at the end go despite him being a Good Father, at least in terms of being lenient and protective.
Nightmare Fuel: Buttercup "accidentally" hitting Bubbles over and over in the hopes she'll lose some more baby teeth is somewhat comedic, given they're both superpowered and Bubbles' will eventually grow a new set. But seeing Buttercup bashing common criminals and taking their adult teeth is akin to police brutality. When that well runs dry, Buttercup just invades the homes of several supervillains while they're sleeping and either hits them in the mouth or rips their dentures out. And the only checks on Buttercup's abuse of her power are her sisters who didn't catch on until she'd racked up a long list of victims.
Meet The Beat Alls provides examples of:
Cry for the Devil: Mojo's a villain and his love-fueled egomania alienated his fellow supervillains, but when he finds out Moko Jono was part of a sting operation — and actually despised him — he's quite distraught.
Narm Charm: The episode is riddled with dialogues consisting of ridiculous The Beatles-related puns, but it's also one of the reasons why many fans fondly remember the episode.
Unintentional Uncanny Valley: The twist that Moko Jono was The Mole comes with her character design suddenly changing so that she resembles a real chimpanzee. The shift can be quite jarring, especially when she bares her teeth. Mojo's startled reaction feels more appropriate than intended.