Hilarious in Hindsight: One episode has Tantor state that "they ought to put warning labels on [scary books]". Nowadays, certain books do have parental advisory stickers, and even ESRB-style breakdowns of objectionable content.
Ho Yay: Max, the journalist in "Tarzan and One Punch Mullargan", is really in awe of Tarzan, with some of his comments sounding like he's got a crush on the ape-man.
Lawful Evil: Lt. Colonel Staquait is a particularly nasty Type IV. He's a high-ranking French Foreign Legion officer who runs the African Cape Doom Prison with an iron fist, works inmates to dehydration, exhaustion, and death, and punishment any kind of weakness or impertinence against him with harsh consequences such as immediate execution. Hugo and Hooft were marked for death as criminals and insubordinate deserters chased down strictly because they disobeyed his direct order to burn down a village of women and children. He even brought a guillotine with him so he could execute the two in a way that was the most cruel simply because he took pleasure in being cruel. It was his behavior that summed up the episode's Aesop as lampshaded by Jane: "Sometimes the people in authority, the ones giving the orders and making the laws, they're the ones who are the real criminals (bad guys)". Ironically enough, the heroes have to break a number of laws (e.g. abetting fugitive criminals to escape, breaking into prison complexes, impersonating government officials like a Magistrate, etc.) to even stop Staquait who more or less follows the law at the time in an exceptionally cruel and ruthless manner.
Magnificent Bastard: Renard Dumont, the smart, cunning and greedy businessman. He shamelessly cheats his clients to make a quick buck, and remains charming while doing so.
When Tarzan and Professor Porter try to stop Professor Philander from caging (and he plans on killing too) the silver ape Mangani, he cuts a rope Tarzan was hanging on, sending him falling several stories to his apparent death. Rather than let Archimedes examine and try to save his son in law, Philander plans on stranding him at sea and tossing Tarzan's body overboard.
Lt. Colonel Staquait crossed it by ordering Hugo and Hooft to burn a village full of mostly innocent women and children. AND then he became obsessed with having them executed for daring to object to this atrocity calling them deserters despite the fact that they had a damn good reason to be.
Nightmare Fuel: Some of the villains can be really scary. La and her leopardmen, Tublat, Mabaya the rogue elephant and Hista the giant python all get their nightmare-evoking moments.
Dania from "Tarzan and the Rift". In that episode, Tantor gets the chance to ask Dania out on a date, but the evening gets ruined by Terk showing up, making noise with household items, and being oblivious to the other characters' feelings. At that point, Dania being alienated by Terk is justifiable. To make matters worse, this is all just a big misunderstanding. The whole conflict could've been avoided if Terk had just apologized to Dania for making such a bad first impression, or at least done something nice to make up for it. But instead, the episode acts like Terk's actions were automatically forgivable. The episode never acknowledges the misunderstanding and expects us to dislike Dania for believing that Tantor should stop hanging around with Terk, despite the fact that her belief is based on Terk making a bad first impression and doing nothing to make up for it.
On the other hand, she meant well the whole time, untill she thought she would lose a friend. Dania simply said he had to choose between his best animal friend and her, while she could have said "wherever we go don't let her anywhere close from me !".
Philander at the end of "Tarzan and the Missing Link". This is mostly because of all the protagonists taking a level in jerkass by being unnecessarily harsh to Philander. Also, Philander only brought those two men to Africa because they were threatening his life. Porter should've at least been respectful while rejecting Philander's offer at the end, instead of literally roaring in his face. However, Porter's attitude becomes more forgivable if you saw "Tarzan and the Silver Ape" before this episode, where Philander crossed the Moral Event Horizon by almost throwing Tarzan to his death, so Porter is understandably fed up with his antics.
Harsher in Hindsight: One of the TV spots features a gorilla carrying an infant Tarzan out of a cradle. This began airing shortly after an incident at the Cincinatti Zoo where a gorilla named Harambe was shot dead after grabbing a small child who fell into his exhibit.