The Call Knows Where You Live: Lion-O receives a vision in The Sword of Omens, but avoids telling anyone. He sees his Kingdom destroyed and his father assassinated by the very enemy whose face he saw in the sword.
Zig-zagged in "Omens," when asked directly, Lion-O doesn't disclose that he saw something frightening in the Sword of Omens, both unaware of its significance, and all too aware of his father's disdain. When Jaga deliberately mentions "Sight Beyond Sight" exists, Lion-O tries to tell him, but receives a gentle Not Now, Kiddo. Too late, Lion-O realizes he saw Mumm-Ra.
Zig-zagged with the Sibling Triangle subplot between Lion-O, Tygra and shared Love Interest Cheetara. Rather than explicitly state that they both have feelings for her and asking if she reciprocates, they complicate matters by treating their interactions as (yet another) passive-aggressive competition, hoping she'll give an indication of "choosing" one of them eventually.
Deconstructed in "Omens Part 1" with one grovelling Lizard prisoner, who fearfully cautions his compatriot that they'll be killed for their defiance when the latter begins to loudly discuss this trope with him in front of Lion-O, right before launching into a full-blown Screw You, Elves! speech. Zig-zagged in that Lion-O actually listens, and later frees them.
Seen again with the "What Lies Above, Pt. 1" when Vultaire and the ThunderCats see each other as the "Elves" as the Cats need the Tech Stone to fight Mumm-Ra, not considering if the Avistains are using it for anything. And the Avistians rub in their own superiority over the Cats and the problems of those "beneath" them. It is subverted for the Cats in the end when they learn taking the Tech Stone would mean the city's destruction and Lion-O and the others, save for Pumyra, won't sacrifice one city for the sake of the world.
In "The Duelist and the Drifter" The Duelist is introduced posed this way, watching Lion-O at a sword competition.
Cargo Cult: Though its existence is both doubted and fabled, Claudus and Jaga place faith in the stories and prophecies of the Book of Omens, while Lion-O is fascinated by its tales of technology.
Carnivore Confusion: We see the Thunderian Cats eating meat, presumably a non-sentient species, but the Fishmen from "Ramlak Rising" have no qualms about eating other sentients. The Cats, unlike the real thing, are depicted not as obligate carnivores, but omnivores like humans.
During Addicus' introduction in "New Alliance", he threatens to eat the Birdmen who are about to execute him. When he's rescued by Slithe, he seems to make good on the offer off-screen.
Cat Fight: Averted. Despite being Lion-O's bodyguard, Cheetara is one of the few who doesn't take a swing at Pumyra when it is revealed she has made a Face-Heel Turn in "What Lies Above, Part 2".
Cat Folk: All the Cats. They're even more cat-like than the original series.
Cat Scare: Parodied and Double Subverted in "The Forest of Magi Oar" when cat-creature Snarf nervously reacts to noises in a supposedly haunted forest, but its only his tricksy Catfolk friends the Thunderkittens who jump out and yell "Boo!" Later on, the menacing spirits show up for real.
Cats Are Superior/Master Race/Superior Species: Thundera's Cats genuinely believe themselves to be the rightful rulers of Third Earth, and its great civilizers, a delusion greatly enabled by their genuine aptitude as physical fighters and possession of powerful artifacts. In this series, they really are the Elves of the Animal Kingdom.
In "What Lies Above: Part 2", the kits manage to bring this with them in their Bag of Holding—containing just about everyone Lion-O helped in their journey, come to repay the favor. Big Damn Heroes ensues.
Central Theme: Right Makes Might. Being a proud badass doesn't make you a good leader. Seeing the big picture, having clarity, doing what's right, and showing kindness, selflessness and mercy towards all does make a good leader, and is the best way to combat the evil in the world that would exploit people's hatred and selfishness.
Character Focus: Primarily Lion-O, though Panthro's introduction, "Old Friends," delves into his backstory.
Chase Fight: The format of Thundera's Gladiator Games. At the climax of "Omens Part 1" Lion-O challenges Tygra to a match only to suffer a particularly humiliating Ring Out.
In "Sight Beyond Sight", Wilykit's flute ends up a critical asset in defeating the stone monster.
Chest Insignia: The Blue Blood, Royal Blood and soldiers of Thundera all sport large red cabochons on their clothing, either chest or belt-mounted, and their shields, meant to evoke their Power Crystal, the Eye of Thundera. It's even present on a Thunderian Sphinx.
Chewing the Scenery: Will Friedle is clearly getting very into it whenever he recites the famous, "Thunder! Thunder!ThunderCats!HO!" battlecry. In fact, it sounds like he's trying to roar the line more often than not.
Chiaroscuro: Used in "The Duelist and the Drifter" while introducing the Duelist, and during the Drifter's Nameless Narrative. The figures are backlit, but their fronts (or their head and shoulders) are near-totally concealed in heavy shadow.
The City Narrows: Lion-O is introduced sneaking cloaked and hooded into the worst part of Thundera's slums, only to catch the eye of a gang of muggers.
City of Gold: Wilykat owns a Treasure Map to the City of El Dara, which he has promised his sister Wilykit they will find together. This quest is what leads them to tag along with the other ThunderCats when they leave Thundera.
Climbing Climax: Inverted In "Omens Part 1" the Chase Fight racing game ends with Lion-O knocked off the treetop and into the water, soundly trounced and publicly humiliated by Tygra as he rings a bell in triumph.
One of the background figures in the town during "The Duelist and the Drifter" wears a samurai helmet, as a nod to Hachiman. Whether it is Hachiman is a coin toss.
The hammer the white-furred blacksmith uses to forge the Sword of Omens in "Birth of the Blades" bears a strong resemblance to the Hammer of Thundera, which in the original series was wielded by white tiger Bengali, and used to reforge the Sword.
Crap Saccharine World: Thundera is at first glance a Shining City, but it also has extensive slums, homeless street-kids who appear to be treated like crap by the population at large, and Gods help you if you're not a Cat.
Crystal Prison: Parodied. The Lizard Army uses a giant geode as a Trojan Horse to enter Thundera, and has been stuck waiting in there for two days, not counting the trip to Thundera. One complains to his general about the smell after being freed.
Cue the Sun: Inverted. Storm clouds part just as The Duelist claims a sword from another unprepared victim, leaving him crushed and defeated as the sun blazes high above his head.
Cycle of Revenge: Especially between the Cats and the Lizards. Implicitly General Slithe's motive.
Dark Is Not Evil: In "Omens Part 1" Deconstructed. As a Lizard prisoner explains to Lion-O, he can hardly be expected to do anything but steal from Thundera's crops since they control the best territories, and habitually oppress and enslave his people.
Possibly Pumyra. The episode hasn't specified whether Mumm-Ra brought her back to life or if she's a magically animated undead.
Deal with the Devil: The Tiger Clan made one with the Ancient Spirits of Evil to save them from a plague. The Spirits demanded the life of the newborn Tygra. Tygra's father couldn't go through with it, and sent him away. The Ancient Spirits damned the entire Tiger clan to a terrible undead existence as punishment.
Defeat Means Friendship: Lion-O is banking on this and in "New Alliances" his campaigns have centered around convincing captured Lizard patrols to return home and encouraging mass desertions.
Subverted with the "liberated" Lizard soldiers; several are seen back in action later. Not that they WANTED to, but they were conscripts to begin with and it's implied that when they were found they were pressed into combat once again.
Deliberate Values Dissonance: It's pretty clear that the Cats are not as incredible and infallible as the Cats themselves believe. In "Omens" Claudus turns a blind eye to a lynch mob going after a stockaded pair of Lizards. When his son Lion-O tries to stop them, he not only actively supports the mob but considers Lion-O weak for showing pity. Lion-O manages to convince Claudus to release them, but later, when the Lizard army attacks, Claudus views it as an example of what comes from altruism. Races like the Lizards, Dogs and Rats similarly take a dim view of the Cats' presumed moral superiority.
Played for Drama and often employed in tandem, with Wilykit revealed as a provider of previously atmospheric flute music, only for a more orchestral version of her piece to begin immediately after she finishes or the camera cuts away.
"Song of the Petalars" Ethereal Choir, by turns is background music, in-universe singing by the Petalars and a more expansive theme after they finish singing.
In "Omens Part One" the first time Lion-O meets Cheetara his voice cracks. Lion-O later feigns this, using the sight of two passing women to avoid mentioning the vision he saw in the Sword of Omens.
In "Journey to the Tower of Omens," Lion-O, trying to master Sight Beyond Sight and failing, gets flustered when Cheetara tries a Hands-On Approach, taking him by the shoulders and telling him to relax.
In the same episode, Tygra openly gapes at the sight of Cheetara using her Super Speed, which Panthro lampshades with a smirk and a chiding "Close that mouth, you're drooling."
Does This Remind You of Anything?: When Lion-O is having trouble using his Sight Beyond Sight, Cheetara puts her hand on his shoulder and tells him to relax and let it come naturally. It's reminiscent of a woman comforting a man about a very different problem. The placement of Lion-O's sword in the shot is very... suggestive.
The master thief Tookit leaves his bag (the doorway to a Pocket Dimension where his thieves are lying in wait) inside a store, which goes unnoticed. This is one way that terrorists place bombs.
Dogfaces: One hapless fellow is mugged by some Cats in the Thunderian slums.
Domino Revelation: In quick succession, Lion-O learns that his people are bigots, and that Precognition, Technology, Mumm-Ra and the Book of Omens are all real.
Double Entendre: In "Journey to the Tower of Omens," Cheetara is attempting to help Lion-O focus, to utilize "sight beyond sight" with the Sword of Omens, and holding him by the shoulders to prompt him, only to be interrupted by Wilykat and Wilykit.
Wilykit: I know what they were doing. *smooching sounds*
Lion-O: No! We were just... trying to get my sword to work.
Double Speak: Lion-O politely claims that his friend Jorma sells "certain hard-to-find collectibles."
Dramatic Irony: Lion-O has no idea what his sudden vision of a pair of red eyes could mean, while the audience knows it's Mumm-Ra.
From whom and from where did Mumm-Ra get the Eye of Thundera? What does it really do? What is the 'bigger picture' that Mumm-Ra talks about with respect to the Book? How did he mass his respective armies, and where did they come from?
Drowning Pit: In "Journey to the Tower of Omens" The ThunderCats are trapped in one of these until Panthro manages to find a secret door and free the others via his Super Drowning Skills.
Duet Bonding: Wilykit and Wilykat with the Elephants in "Sight Beyond Sight." Their flute and the elephants' natural trumpets turn out to go very well together and before too long, they have the entire village joining in - until they hit a particular frequency and stone sculptures near by shatter. This turns into a Chekhov's Gun when they use the stone-shattering trumpeting against the Rock Biter attacking the village later on.
Panthro is commemorated at a festival table with a Shrine to the Fallen made of his painted portrait and his nunchucks on an altar, while his friends feast alongside it, toast him, and dedicate some games in his memory.
Claudus receives a quiet funeral pyre as Lion-O carves his royal emblem into the base of his destroyed monument.
Dungeon Bypass: You are in a room. There is a narrow platform that is suspended over a pit of spikes. On the other side of the platform is a door with a keyhole. Hanging above are hundreds of keys. One will open the door, but choose wrongly and the platform retracts, spilling you into the pit. What do you do? According to the Thunderkittens: Pick the lock.
You are in a maze. There is a key in the center. You have to find a way to get it before someone with Super Speed who already knows the way through the maze gets it or you stay dead. What do you do? According to Lion-O: Fly over the maze.
Played with; Lion-O was SUPPOSED to do this, as it was literally impossible to beat Cheetara in a footrace over such a relatively short distance, especially when she knew the correct path to start with. It was to teach him that sometimes the direct, head-on approach isn't always the best one. It's only about the third or fourth time he learns it.
During the War: The series is set against a backdrop of a generations-long war between the Cats and the Lizards, newly rekindled thanks to the intervention of Mumm-Ra and his Dragon, the turncoat Thunderian General Grune.
Elves Versus Dwarves: In this production, the Elves will be played by Cats and the Dwarves by Lizards.
Embarrassing Rescue/Grudging Thank You: Inverted and downplayed: When Lion-O is saved from a mugger's headlock by Cheetara, he responds with "Not that I needed it, but who can I thank for the assist?" Only on saying goodbye does he offer "Maybe next time I can bail you out of trouble."
Empathic Weapon: The Sword of Omens chose Lion-O to wield it. It also refuses to harm a force of good. This helps Lion-O realize that Viragor, the forest guardian, and the spirits in "The Forest of Magi Oar" aren't the bad guys. The sword working against Headmaster Zig, along with the his refusal to negotiate with Viragor, convinces Lion-O that the Wood Forgers are just as bad as the guardian claims.
The Empire: Thundera. Just ask anyone who isn't a Cat. As it is, the Cats probably consider Thundera an Empire too, they just don't consider it a BAD Empire.
Epic Tracking Shot: Though cheated with stills, this serves as the sweeping introduction to Thundera during Jaga's Opening Monologue, from the lands surrounding the walled city to a close-up of a frieze on the wall of the palace courtyard, containing some prophetic bas-relief.
Et Tu, Brute?: Poor Claudus gets this twice. First his most trusted general helps his enemies destroy his city. Then he's stabbed In the Back, after rescuing his other trusted general Panthro from capture. As soon as Lion-O asks "You, a traitor too, Panthro?!" the second betrayal is subverted, and Panthro is revealed as Mumm-Ra in disguise.
In "What Lies Above" part 2, Lion-O experiences this when Pumyra hands over the Tech Stone to Mumm-Ra.
Evil All Along: Pumyra never did forgive Lion-O, she just lied about it. She originally died during the fall of Thundera and was raised by Mumm-Ra to exact vengeance by joining the ThunderCats as a spy for him.