Ever since King Kong brawled against several prehistoric monsters in his 1933 debut, and more famously against Godzilla in King Kong vs. Godzilla — pretty much cementing the two in pop culture as the iconic battling kaiju — filmmakers (and other creators) have found the image of a giant ape (or a primate-like creature) fighting a giant reptile too iconic, symbolic, and just plain awesome to resist. As a result, dozens of homages to the scene have sprung up over the years, as well as variations on its imagery and themes.
The primate may be a giant ape, a protohuman, or an ogre, a giant, a cyclops or other humanoid monster with ape-like features, whilst the reptile may be a dragon, a dinosaur, or a giant snake/lizard/crocodile/turtle.
The primate will use its fists, its intellect and the occasional Improvised Weapon, whilst the reptile will use its teeth, claws, and brute strength; if venom, constriction and/or fiery breath are available, those will be used too. Expect the reptile to have the size advantage, too.
Symbolically, the trope works because the primate is automatically more relatable, therefore more sympathetic, than the more repulsive reptilian monster (because Reptiles Are Abhorrent).
When the opponent is a dinosaur, it works as a Clash of Evolutionary Levels - the more "modern" primate fighting and more often than not defeating the more "primitive" dinosaur calls back to the mammals' supplanting of reptiles as the dominant animal class on Earth following the K-T extinction, to which humanity owes its existence. The inverse to this point-of-view is that the dinosaurs are an "elder race" that is stronger, wiser, more advanced, firmly established, and much more accomplished than the primates who are a "younger race" and thus largely unequal and inferior to the dinosaurs as a civilization and species.
A clear subtrope of Behemoth Battle. The giant ape is generally a King Kong Copy; however, that's not always true. Similarly, the giant reptile is often a Notzilla or a T-Rexpy, if it's not based on a real dinosaur. Compare Spinosaurus vs. T. rex, a similar monster fight in which both fighters are reptilian, as a Stock Shout-Out to a much later movie.
On a side note, it should be noted that, while Homo sapiens is indeed a member of the primate family, this trope relates mostly to non-human primates, so the numerous works such as Anaconda, Lake Placid, and the like that feature average (or super) humans battling snakes, crocodiles, Velociraptors etc. don't apply here. Similarly, birds are technically classified as reptiles, being dinosaurs and all, but this trope only refers to reptiles in the traditional "scaly" sense, so works with primates battling birds and feathered non-avian dinosaurs also don't apply here.
- Zigzagged in Kaiju Girl Caramelise. Two of the main characters are Raimu "Rairi" Koumo, who has an apelike face that she conceals with heavy makeup, and Kuroe Akaishi, who involuntarily and secretly transforms into a massive dinosaur-like monster called Harugon when experiencing strong emotion. They become fast friends almost as soon as the two first meet due to their similar insecurities over body image. However, Rairi has no idea Kuroe is Harugon, and at one point the former, without her makeup and with her ape face unconcealed, roars at the transformed latter to defend their classmates. Kuroe/Harugon quickly backs off into the lake, partly because she's startled at Rairi's actions and partly because she still respects her ignorant friend.
- Toriko has, at one point, a colosseum where monstrous animals fight for the entertainment of rich and powerful elites. The first battle shown on page is a duel between the gorilla-like Troll Kong and the massive, eight-legged Gararadile. Despite being smaller and being manhandled by the latter, the Troll Kong manages to win by cracking the skull of his opponent with an extremely precise attack.
- In Dragon Ball Z, while the obvious traits are downplayed, Goku's battle with Frieza is this, as Goku is a Sayian, a race of humanoid monkey-like aliens, while Frieza is of a humanoid reptilian race.
- The defunct Disney Adventures had a comic called Gorilla Gorilla, about two roommates, Gorilla Gorilla and Lizard Lizard, who habitually transformed into colossal versions of themselves and did battle. However, neither of them knew the other was actually his arch-nemesis.
- In an early story of The Goon, the mutated lizard El Hombre Lagarto grew to colossal size, and the Goon himself had to be temporarily transformed into a giant gorilla so they could fight.
- One of the Jurassic Park Expanded Universe comics by Topps/IDW features a trained gorilla taking on two Velociraptors. The gorilla loses.
- Kaiju Revolution: Skull Island's protector King Kong is involved in several of these in both series proper as well as his backstory.
- It's mentioned in his backstory that he had a rivalry with the leader of the Gorosaurus pack that would lead the two of them to develop a mutual respect for one another. Eventually when the Vagnosaurus invaded the surface, the two were forced to work together to drive them back, this would lead to them becoming full fledged allies who now work together in protecting and maintaining the island.
- He fights Godzilla when the King of the Monsters shows up to devour the island's inhabitants. He's able to match Godzilla at first but Godzilla's raw power nearly overwhelms him untill Gorosaurus and the island's native kaiju assist him. Kong is able to force Godzilla into the ocean and bury him in a rockslide.
- Then there's his most hated enemy: the subterranean Vagnosaurus. Their two species went into a mutual destructive war that would leave Kong and a single Vagnosaurus clan as the Last of Their Kind. Kong eventually kills the clan's matriarch and leaves them to dwindle to extinction. This last one is a subversion however as despite their name and apperance, the Vagnosaurus aren't reptiles at all but actually primates which have evolved into vicious, hypervorous predators in Skull Island's underground caverns. In fact, they are actually descended from the same basal primates that Kong's species descended from.
- The latest example would be Gaw, a despotic kaiju raptor that killed Kong's parents during the Vagnosaur wars and had to be sealed away by Biollante. After being freed in the chaos of King Ghidorah's attack on Skull Island and Kong's subsequent disappearance, she's quick to start a takeover of the island and takes steps to stop Kong when he's brought back to earth and starts making his way back home.
- The Bridge: Sets up but subverts it as far as the two Godzillas of the 1990s and the MonsterVerse King Kong. Godzilla Junior ends up on Skull Island for a year and meets Kong early on, but his docile nature and attempt to protect several Iwi from a skullcrawler means Kong doesn't register him as a threat. Junior actually takes a shine to Kong and begins copying him from a distance, and overtime Kong warms up to him as a sort of pupil.
- Godzilla Senior comes to Skull Island to reclaim his lost son and is fully prepared to attack Kong when he sees the ape near his adoptive child. King Kong registers him as a threat and is prepared to attack to protect his island and pupil, but Junior manages to defuse the situation.
- Invoked and averted in a fanmade Treehouse of Horror segment where Bart, having gained Reality Wraping powers, conjured up King Homer and Homerzilla for them to fight. Rather than brawl for his amusement, however, the two monsters teamed up and rampaged through Springfield.
- Pretty much every incarnation of King Kong has had one of these fights.
- The Trope Codifier is King Kong, in which the titular ape fights a Tyrannosaurus rex, a serpent-like plesiosaur and a giant pterosaur.
- In the largely-forgotten sequel, Son Of Kong, his son battles a nothosaurus, and early relative of the plesiosaurs and pliosaurs.
- King Kong vs. Godzilla is Exactly What It Says on the Tin: a fight between Godzilla and Kong.
- King Kong Escapes: Kong fights the theropod-like giant monster Gorosaurus and a sea serpent.
- King Kong (1976): Although there are no dinosaurs in this film, Kong gets to fight a giant snake.
- King Kong (2005): The film ups the stakes by Kong fighting not one, not two, but three Tyrannosaurus (named Vastatosaurus in this film, a fictional genus that is supposed to be the descendant of Tyrannosaurus).
- In The 7th Voyage of Sinbad, the dragon that serves as Evil Sorcerer Sokurah's Right-Hand Attack Dog fights a Cyclops; given that neither party is meant to be particularly heroic (although the dragon is a Tragic Monster), the dragon wins.
- In Frankenstein Conquers the World, the antagonist is Baragon, an enormous, tunnelling, predatory reptillian monster, as opposed to the Gentle Giant mutated human Frankenstein.
- In Rampage (2018), the climactic battle of the film is between the gigantic gorilla George and the even more gigantic crocodile Lizzie, after Lizzie quickly kills George's previous opponent, Ralph the giant wolf.
- The Adventures Of Hercules II has a scene where King Minos uses the powers he got from the Gods to turn into a giant T. rex, then a giant snake. Hercules, in response, turns into a giant ape. The fight is hand-drawn animation traced from the monster fights in King Kong (1933).
- In Scott Pilgrim vs. The World, during an amp-versus-amp Battle of the Bands, Scott's band Sex Bob-Omb summon an Animal Battle Aura of a yeti, and their rivals, the Katayanagi Twins, summon a pair of serpentine dragons to fight it.
- Spy Kids 2: Island of Lost Dreams has a Mix-and-Match Critters variation, with a Spider Monkey (a caveman-spider hybrid) being pitted against a Slizzard (a snake-lizard hybrid).
- In Bloodbones, at one point you can run into a gigantic ape battling a "terrible lizard". You may end up fighting the winner of the clash.
- Super Smash Bros. Melee has an event match wherein Bowser and Donkey Kong (both appearing much larger than normal) fight on Fourside, an EarthBound-themed skyscraper stage—an obvious homage to King Kong vs. Godzilla.
- Being a homage to the Kaiju and Tokusatsu series, the King of the Monsters series has expies of King Kong (Woo/Cyber Woo) and Godzilla (Geon/Super Geon), being a giant ape and a reptile, respectively, fighting against other giant monsters as well against each other.
- The 16-bit game Primal Rage was about prehistoric beasts fighting... with the villains led by the tyrannosaurus Diablo vs. the Virtuous Beasts led by heroic ape Blizzard.
- Donkey Kong's most recurring nemesis is the crocodile King K. Rool.
- Dragon Age: Inquisition: the party can potentially come across a battle between a decidedly simian appearing troll and a High Dragon, which the Iron Bull will note is awesome.
- Monster Hunter has long featured two particular monsters regarded as possessing the strength of an Elder Dragon while not actually being one: the primate Rajang and the dinosaur-like Deviljho. Comparisons and contrasts between the two were inevitable, and they do share a Turf War together in World, where they battle to a draw.
- The two principal gods in Dragon: Marked for Death are the draconic Atruum and the simian Primatus.
- An episode of The Grim Adventures of Billy & Mandy has Billy and Irwin watching a cheesy Japanese movie where a Kong expy fights a robotic pterosaur.
- The Simpsons:
- In the third Halloween special, Abe tells a story about "King Homer" (a parody of the 1933 King Kong film). Homer was seen fighting a T. rex before being summoned by the natives.
- In "Wedding for Disaster", Homer worries that Marge is turning into a Bridezilla, promoting her to call him "King Wrong". This causes Maggie, who is watching their spat, to imagine them fighting to the death as Kong and Godzilla, respectively.
- In Transformers: Beast Wars, Optimus Primal transforms into a gorilla and Megatron transforms into a Tyrannosaurus rex. The opening theme song even ends with a scene of Megatron attempting to bite Primal's head, while Primal holds the jaws open with his bare hands.
- Rugrats: A variant in the episode, "Toy Palace". When Tommy and Chuckie get locked inside the titular toy store, Tommy at one point accidentally turns on a life-sized doll of Thorg the ape, which chases him and Chuckie throughout the store. Tommy later manages to turn on a life-sized doll of Reptar the dinosaur, which pushes the Thorg doll into a Time Machine, which takes it to the time period where Washington crossed the Delaware River.
- The Primal (2019) episode "Rage of the Ape-Men" has a fight between the ape-man warrior Krog who is under the effect of a strength-inducing serum that turns him into a King Kong Copy and the tyrannosaurus Fang. The roles are very much inverted, as Fang is sympathetic and one of the protagonists, whereas Krog is the cruel champion of the evil ape-men.
- An episode of Disney's The Legend of Tarzan has Moyo, a gorilla who has just wrested leadership of the apes from Tarzan, attempting to defend the colony from a giant python named Histah and being unable to do so without Tarzan's assistance.
- Kong: The Animated Series: Par for the course, given that not only is Kong Island populated with dinosaurs—most of whom were actually docile toward Kong and his human allies but, you know, Tyrannosaurus rex and raptors—but the Big Bad and his flunkies had the ability to merge with animals of their choice, many of these being reptiles, naturally.