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.
Bizarro Episode: Robo Frog 3000. The plot has the school board replacing Principal Pixie Frog and the rest of the teachers at Charles Darwin with robots(called robuts by everyone in the episode) and plan on replacing the students with robots, the teachers and Pixie Frog bringing out a wizard in their trunk to fight them, the school board bringing out a robot wizard that defeats the other wizard, and the robots eventually exploding due to running out of love. Adam and Jake lampshade this while the robots are exploding
That episode where Jake was transferred to a plant school after a clerical error and no-one questions it. That episode was dumb even by this show's standards.
Moral Event Horizon: Nurse Gazelle crosses this in The Hyena And The Mighty when she chases Rufus Hyena trying to shave his fur off. Doesn't seem too evil? Well, Rufus was in a state of shock and depression and was busy crying his eyes out because Adam insulted him. The nurse doesn't care about Rufus' well being, she outright TERRORIZES him while he's in a sad mood by chasing him with clippers just so she can make herself laugh. Also, keep in mind that Rufus is only a kid and would most likely get emotional scars from the incident.
So Okay, It's Average: General consensus of that it was very mediocre show with some genuinely funny moments.
So Unfunny It's Funny: The nerds of the class were joking about Adam's stupidity (which he was obfuscating) which lead them to make fun of his name from Adam to A-dumb. It was a clever pun that is, until one kinda ruined it by saying: He's so dumb his name should be "Ad-stupid". Unfunny In-Universe but it counts as one of its Funny Moments from some viewers.
Squick: Several episodes has this. There's Ingrid's constant crushing on Adam. And in the special Glazed And Confused, there's a scene where Adam applies sunscreen on Jake's behind. Even Adam points out "it's just wrong."
In episode "Guano in Sixty Seconds", Jake was eating (what everyone and himself believed to be) a bag of popcorn, when asked by Adam where does he keep getting it, Jake reaches up to the ceiling and scraps off more popcorn, to which a horrified Adam tells him it is asbestos. Windsor calmly tells him that it isn't asbestos, but as it turns out it was bat guano.
Many Jake's butt jokes are this.
Tear Jerker: The Hyena And The Mighty, particularly to people with mood disorders who were bullied as children. The scene where a tearful Rufus Hyena goes into a Troubled Fetal Position after Adam insults him behind his back is particularly sad.
The Woobie: Rufus Hyena from the episode The Hyena And The Mighty is easily the biggest woobie on the show. The only episode he was ever in, he suffered from severe Break the Cutie. Once Adam insulted him and his laughter, he stormed out of the bathroom in tears and actually went into a Troubled Fetal Position at one point. He was in a constant state of Ocular Gushers and Adam barely felt any remorse for having hurt his feelings. Not once did Adam feel the need to apologize to Rufus, even THREATENING him to stop crying at one point. Also, Nurse Gazelle terrorizes him for no reason by trying to shave off his fur while he's in his tearful state.. The only ammount of sympathy Rufus even got was Windsor cuddling him and Jake feeling concerned about him. Adam, Principal Pixiefrog and Nurse Gazelle treated him like garbage, not giving a damn about his hurt feelings.
Henry has his moments too.
Vice Coach Horace Ferret, who may be being used by Coach Gills only as a means of transportation and she may not care about his feelings.
Cyrus Hornbill also has shades of this.
Ingrid Giraffe, due to being the tall awkward girl of the class. The way she gets treated in Ingrid Through The Outdoors is pretty unnerving yet she is one of the sweetest characters on the show.