Huge Rider, Tiny Mount

[The planet Vogsphere had] "... elegant gazellelike creatures with silken coats and dewey eyes which the Vogons would catch and sit on. They were no use as transport because their backs would snap instantly, but the Vogons sat on them anyways."

—The Hitchhiker's Guide to the Galaxy

Quite simply, this is the instance of a very large rider riding on a very small animal. It's often spotted in comedies as a way of providing Comic Relief if the rider is too intimidating to suit the tone of the story. The implications of this situation are very rarely discussed; as far as anyone will see, the mount will never tire out from carrying such a heavy weight or appear harmed in any way.

Examples of Huge Rider, Tiny Mount include:

Anime and Manga

In Transformers Cybertron, this happens with two Decepticons named Ransack and Crumplezone - Crumplezone winds up riding vehicle-mode Ransack even though 1. both turn into motorcycle-like vehicles and 2. Crumplezone is built like a gorilla and about eight times bigger.
Pokémon:
- Gone to ridiculous lengths in an episode of the anime, where the cast had to race on Pokémon provided to them. Most absurd examples are Ash hopping on a little Spoink, Jessie getting pulled by a Magikarp on the water, and what can best be described as Recurring Character Conway being dragged on the ground by a Dugtrio.
- In the episode, "Clefairy and the Moon Stone", Pikachu manages to pick up a Clefairy, a Pokémon who is larger and heavier than him.
The Freaky Friday episode of Beelzebub.

Comic Books

One of She Hulk's fourth-wall straining sequences had her as a character in Elf Quest, where wolves are quite reasonable mounts. She-Hulk tries this and of course horribly slays the poor beastie.

Film

Disney's Aladdin features an inversion. The Arab vendor at the beginning of the movie is a comically small man, but his camel, although huge, tires out and collapses. Then again, he was also carrying all of the vendor's wares at the time, but this isn't revealed until a moment later for comic effect.
Quest for Camelot is famous among animated film buffs for never appearing to have half a clue as to what it's doing. One such instance features presenting a series of genuinelly dangerous-looking monsters, and then giving them tiny funny little warthogs to ride, completely ruining the effect. The ensuing action-packed chase scene is also accompanied by a gentle ballad on its soundtrack.
In the "Pastoral Symphony" segment of Fantasia, Bacchus comes in riding a tiny unicorn-donkey (which the animators called Jackus), both tipsy from drinking wine.
How to Train Your Dragon gives us the intentionally comical example of the stoutest member of the teenage vikings, Fishlegs, riding the smallest dragon, the Gronckle.
Subverted in the Yosemete Sam cartoons where Sam bounces atop a horse that is way too large for him and has to resort to jumping off it and beating it over the head in order to get it to stop as he's so tiny in comparison to it that hauling on the reins makes no difference at all.
Austin Powers: In Goldmember, Austin and Mini-Me do a Totem Pole Trench to sneak around Dr. Evil's lab. Mini-Me was on the bottom.
Invoked in dialogue in Thor when the main character walks into a pet shop and demands to be given a horse. When he realizes there are no horses, he points to a puppy and says, "Give me one of those, but big enough to ride."
In "Black Narcissus" an Englishman is working as an agent for a local noble. He's shown coming into view riding a tiny pony with his feet barely above the ground. I suppose it's the biggest horse you find in the Himalayas.

Literature

A Song of Ice and Fire: Gregor Clegane, The Mountain That Rides. It's less of a tiny-mount situation and more of a the-guy-is-so-frikken-huge-that-a-Percheron-on-growth-hormone-would-be-tiny-by-comparison situation.
The Hitchhiker's Guide to the Galaxy, on one of its narrative asides, mentions that back when their home planet was still inhabitable, the Vogons would ride a sort of gazelle-like creatures for entertainment. The Vogons are huge, monstrous things and the gazelles were small and sleek, meaning that sitting on one would break its back and kill it... but the Vogons sat on them anyway (not surprisingly, since they're supposed to represent everything daft and stubborn about humankind).
Discworld: Rincewind in The Last Continent. The twist being that the mount didn't have to be so small (it had powers) so was only doing so to be pissy.
In The Wheel of Time, while Loial's horse is a huge draft beast, the fact that Loial is about 9 feet tall makes it look like a pony when he rides it.
Averted in Belgarath The Sorcerer; Algar doesn't want to ride because he's so big in comparison to a horse that his feet would drag on the ground. This is mostly because Algar, his brothers, and his father are all very large even by Alorn standards. According to Belgarath, horses at this time (post-cracking of the world, but still very early in the planet's history) were also much smaller than "modern" horses. (Within 16 years, Algar's people have managed to breed horses large enough for Algar to ride. There's no word on whether Belar cheated or David Eddings flunked biology.)

Live-Action TV

Red Dwarf: When Lister employs the "steed cheat" in a Medieval knight VR game, the enemy knight's magnificent steed is replaced by the tiniest little donkey you can imagine.

Mythology

The Hindu god Ganesha, who is a plump Big Eater, rides around on a rat.
According to Christian scriptures, Jesus entered Jerusalem on Palm Sunday riding a donkey.

Video Games

Super Mario Bros. series:
- Yoshi is about the same size as Mario in some games in the series.
- Paper Mario: The Thousand-Year Door: The Yoshi party member in features this trope. He's maybe about half the size of Mario, tops, and yet Yoshi can not only carry him around, he can run twice as fast as Mario can on his own and even fly for a short time, without ever tiring out. He can even carry two people at one point. However, he is a Cute Bruiser (and a loudmouth) who enjoys fighting in the Glitz Pit, so carrying Mario probably isn't a hassle for... whatever you call him.
- Paper Mario, Mario's party member, Sushi, is a fish that Mario is twice the size of, yet she is able to swim in the water with Mario riding on her back.
- Super Mario 64 features a small owl who carries Mario to the top of a tall tower in the second stage. He does tire out eventually, though.
The Donkey Kong Country series is made of this trope.
- Animals ridden by a large ape at some point or another? A frog, a parrot, a snake, and even a freaking spider. Granted, there are other, larger animal buddies that don't invoke this trope, such as Rambi the rhinoceros and Enguarde the swordfish.
- Donkey Kong Jungle Beat also features Helibirds, weird duck-parrot hybrid thingies that can carry Donkey Kong around by their talons, but these do tire out if DK has too many bananas on him (and, generally, that game is more reasonable regarding the size and species of the animals Donkey Kong can ride).
- The prime example is Donkey Kong Country 3, where Dixie is giving Kiddie a piggyback ride; appropriately, this causes her to slow down and not jump as high.
Banjo-Kazooie features this trope when Kazooie runs around while Banjo rides on her back. It's incredible how she manages to maintain such fast speed even with the weight she is carrying.
World of Warcraft
- Every race has a mount favored by its culture. For a long time, only gnomes and dwarves could ride the former's mechanical emus since the other races were too big. Conversely, the tauren are so large, they couldn't ride any mounts except their own (a dinosaur), the orcs' wolves, and the aerial taxi mounts (though watching them ride the Undead's bats makes you pity the poor creatures). However, a patch was eventually released that allowed anybody to ride anything. If the mount's original size is too small for the character, it's simply scaled up.
- But even this doesn't always work. Tauren still look ridiculous on hawkstriders (basically tie-dyed ostriches), and male draenei look odd on horses and mechanostriders. Even with the scaling, it still doesn't always seem in proportion.
- In one of the early Death Knight quests, the fledgling Death Knight is instructed to steal a horse to earn his steed. A Tauren stealing a pony and riding it back to the Scourge base camp is one of the funniest things you will ever see. It's too bad that when he gets his Deathcharger, they are all standard horses, scaled appropriately, and they don't get to keep the one they steal.
- In Wrath of the Lich King, one of the quests in Storm Peaks involves the character taking on the disguise of one of the Hyldnir - large blue frost giant/viking women (incidentally with huge ... tracts of land) - who are significantly larger than the player character. If you fly over the region on one of the standard faction flying mounts, your character will automatically take on the disguise, becoming at least as large, if not larger, than your mount. If you are riding a gnomish Mechastrider or Dwarfish ram ground mount in the area, you wind up significantly larger than your mount. (Especially jarring if you are playing a gnome or dwarf character as well.)
- There is also a limited use version of this with the mount 'Tiny' from the trading card game. You get 50 uses of a ludicrously undersized horse/raptor (if you are alliance or Horde, respectively).
- Another subversion: Before the Cataclysm expansion, all Paladins were given regal horses as their mounts, despite how silly male Draenei look on horses, as mentioned above. But this would obviously not work for the new Tauren Paladins, so they were given Sunwalker Kodos instead. It's possible that the developers were designing them and remembered how odd male Draenei look on horses, because now Draenei Paladins have their own specialized mounts too.
- And played straight again with the camels available from a faction in Uldum and some of the larger races.
Averted in Majoras Mask. If you attempt to ride Epona while wearing the Goron mask, Tatl will stop you. "You'll flatten the poor thing!"
- The same goes for when wearing the Zora mask. Tatl informs you that you are taller than Epona, and that riding is right out.
- There is a glitch that allows you to ride in any form, though. Riding as a Goron looks just as funny as you would expect.
An odd example born of Gameplay and Story Segregation: some very small Pokémon can be taught the HMs Fly and Surf, then be used as flying and swimming mounts. Which leads to some... interesting imagery. Generation III onward ignores the visual ramifications of this trope: when used, Fly and Surf are shown as generic large birds and whales (the former resembling Swellow, the latter Wailmer) carrying the player, with the actual specific Mon not shown.
Tails can carry Sonic the Hedgehog for quite a distance, considering he's half his size and flies by whirling his tails like a helicopter. Same case goes for him carrying other Sonic characters such as Amy.
Rift: A male bahmi (the towering stouts of the Defiant faction) on a vaiyuu (somewhere between a gazelle and an Oviraptor). Hard to decide to whether to laugh or worry that the mount is about to collapse.

Web Comics

Awkward Zombie parodies this in a comic about an expansion pack for World of Warcraft which would allow no weight restrictions on mounts.
A Brawl in the Family strip starts with Mario riding Yoshi, and Kirby asking if he can try it. Mario agrees, and the third panel shows him riding on Kirby, who is straining to carry him.

Western Animation

In the Looney Tunes cartoons featuring Daffy Duck and Porky Pig as Western lawmen, scrawny Daffy rode a glorious steed, but portly Porky rode a diminutive burro that looked as though he couldn't carry so much as a heavy quilt. Their nemesis, outlaw Nasty Canasta, rides a horse that's much, much too small for his enormous figure.
Barney Bear rode a very small donkey in "The Prospecting Bear".
Total Drama World Tour: Done Up to Eleven where the five members of Team Chris Is Really Really Really Really Hot, including Owen, ride a single goat.
Family Guy:
- Peter always wanted to ride Brian like a horse, but obviously that wasn't happening. One day Peter discovered liposuction! Yep...
- Peter has been shown riding on Brian, a water-skiing girl (on the cover of a magazine), and even his wife, Lois (at least that's what the episode made us think)!
Mickey Mouse can sometimes be seen riding his dog, Pluto.
In some episodes of Scooby Doo, Scrappy is shown carrying Scooby and Shaggy at the same time!
Several times in 101 Dalmatians: The Series, Cadpig has been shown supporting Lucky (who is twice her size) on her shoulders without consequence.
There is one episode of Fantastic Max where FX was able to carry Max on his shoulders, despite the fact that he's a little bit smaller than Max.
On Jimmy Two-Shoes, Cowboy Stackhouse rode a horse half his width and a third his height.

Real Life

Some birds of prey have been known to steal lambs. Attempts on small children are not unheard of!
Genghis Khan and his Mongol hordes were known to ride around on sturdy, but small, mountain ponies.
The world's fattest twins and their motorcycles. Enjoy^{[dead link]}.
Vikings rode on horses that were around 130–150 cm at the shoulder.