This trope describes when a particular element of a story or setting has been expanded to the point that there's a version to suit every viewer's preference. Another way to describe it might be "a taste for every appetite".
A codifying example would be the Elf as portrayed in the Dungeons & Dragons tabletop roleplaying game, where the basic "Elf" player race found in the Player's Handbook quickly branches into Dark Elves and Wood Elves in the Monster Manual/Dungeon Master's Guide, and in other official sourcebooks includes Gold, Grey, Sun, Moon, Wild, Sea, High, infernal and celestial variants, Half-Elves and Avariel, just to name a few. Third-party books include countless further versions.
This trope is tied to most "Our x are different" Tropes, but isn't quite the same; this trope denotes the explosion of "difference" in a single series or setting, rather than just the varied interpretations of an idea between settings. The Cast Full of Pretty Boys and Improbably Female Cast can also be examples of this trope, since they generally exist to provide a large cast catering to a number of niche archetypes and fetishes/paraphilias.
The vast selection of deities in most polytheistic religions is a real-life Ur-Example of this trope.
Romance Games do this all the time. For Otome Games and Boys Love Games, there's a standard cast: The rich guy, the energetic, straightforward guy, the cool, aloof guy with glasses, the athletic guy, the guy who is pretty as a girl, the "cool older brother" type, and the suspiciously young-looking guy.
In a case where the setting Tastes The Rainbow on a cosmological level, it's probably a Fantasy Kitchen Sink where every conceivable mythological creature/hero/pantheon shows up at some point.
The title comes from the advertising slogan for Skittles candy.
- Gakuen Heaven is a Boys' Love series set at an exclusive high school that includes every archetype of guy there is - and all of them are hot.
- Negi's class in Mahou Sensei Negima! is a walking case. It covers almost every imaginable female character trope appreciated in anime, and at least suggests most of the fetishes. If we extend that range beyond the class itself, we hit pretty much every conceivable form of romantic or sexual appeal at some point. As well dozens of iterations of Rule of Cool.
- The entire point of the Ouran High School Host Club (the titular club, not the series itself) is to cram in as many different forms of female-aimed fanservice and types of hot guy as possible.
- Martial arts in Ranma ½ fit this trope perfectly. No matter what hobby, lifestyle or animal you can imagine - from flower-arranging to breaking and entering - somebody in the Ranma universe has made it into a martial art.
- The World God Only Knows makes sure to include every single female archetype found in a Romance Game — with a few curveballs to make the Genre Savvy protagonist's life harder.
- Saint Beast has bishonen of every shape, size, Character Alignment, archetypal personality, and shipping potential a fangirl could want. And they probably do cover the entire rainbow as far as hair colour goes.
- The class in Sayonara, Zetsubou-Sensei is like Negi's, but with severe personality disorders instead of fetishes (well, they're probably someone's fetishes....)
- Queen's Blade. If it's fetish material, then it's represented by a character in this universe. Examples include Lesbian Vampire Maid, Yandere Cat Girl warrior, and an Action Mom who can use her own huge tracts of land as makeshift pillows.
- Femme Kabuki is like the above except invoked and intentional In-Universe given they're a Meiji Era burlesque/Hooker with a Heart of Gold troupe that correspond to the fetishes of the day whether an Oiran Team Mom, a Token Mini-Moe saving herself for a boyfriend back home, a Tomboy and Girly Girl pair of Vitriolic Best Buds, Foreign Fanservice that's actually But Not Too Foreign or The Ingenue implied to be the star of the show.
- The Adventures Of Olivia is this when it comes to race, ethnicity and if nothing else occupation as the title character's a Black woman with giant afro-puffs, Mexican Lupe, Italian Anna, Jewish meganekko Naomi, South Asian Fatima, Sandy Shores, Native American Penny, East Asian Mi-Hy and rich-as-fuck and so, so '80s opulence Sylvia having theme episodes like being nurses, wearing bikinis or going to the gym.
- Polytheism is parodied in Discworld, where there is a god for just about every niche you can imagine (Anoia, the Goddess of Things That Get Stuck in Drawers, is probably the most commonly-seen example.)
- The list for The Dresden Files isn't quite as numerous as some of the other examples, but Harry has faced off against three highly varied species of vampires, with another species mentioned offhand (thankfully, none of them sparkle). There's also just about any variation of faerie you can imagine (along with more than a few you'd rather not.) And most of a chapter in the second novel is devoted to explaining the various types of werewolves.
- Fighting robots in Real Steel show a tremendous amount of variation apart from their humanoid shape.
- Super Sentai / Power Rangers. Ignoring the multicolored spandex jokes, there's been a Ranger team for just about anything that falls under the Rule of Cool: dinosaur Rangers, ninja Rangers, car Rangers, space Rangers, beast Rangers, wizard Rangers, police Rangers, samurai Rangers, pirate Rangers, etc. The franchise has gone on long enough that some of these have been done twice or even three times.
- As above, the Dungeons & Dragons RPG illustrates this trope beautifully with elves, and occasionally dwarves (though the dwarves tend to have very little actual variety.)
- If elves are the best D&D example, dragons are certainly second. Chromatic (evil-aligned) and metallic (good-aligned) groups reside in the core books, along with not-quite-dragons like pseudodragons, drakes and fairy dragons, while later expansions introduce the various gem (psionic/neutral-aligned) varieties, shadow, fang, force, prismatic, sand, pyroclastic, stygian, and various oriental versions (once again, just to name a few.) Of course, dragons also seem to breed with anything that moves, meaning there are also countless "draconic" versions of other critters as well. There truly is a dragon for every season, and probably every hour as well.
- It was a joke for a while among the Exalted developers that the only perversion that didn't exist in Creation was Pyrohomonecropedobestiality: "Having sex with a dead underaged animal of the same gender that's on fire." Not that the game lacks the tools to make a god for such a purpose. Creation operates on a modified version of Rule 34: if it exists, there's a god for it. No exceptions.
- Clans and Bloodlines in Vampire: The Masquerade eventually became this.
- In Warhammer 40,000, there's a space marine faction for whatever particular flavour you like. The same is true of Imperial Guard, where every guard faction is an expy of a real-world military stereotype, complete with a faction who define themselves by surrendering.
- Japanese Romance Games do this all the time. Now imagine if every single beautiful woman from every single Eroge duke it out in a card game. That would be the general feeling of Lycee TCG. Characters that share archetype also share "colors" and Standard abilities, but each character has her (or hisnote ) unique Character ability.
- Touhou. It's doing its best to include an Improbably Female version of just about everything from Japanese folklore, along with a few Chinese and Western myths.
- The Harvest Moon series is playing into this more and more each generation with their bachelors and bachelorettes. There's almost always a Girl Next Door, a weird girl, a Tsundere, et cetera, et cetera.
- The Idolmaster uses this as premise for including in the cast every possible Moe archetype.
- Shin Megami Tensei: The archetypal Mons series. If it's a supernatural creature or god from folklore (old or new), you can recruit it. And before/after that, you will kill it.
- Total Drama - 22 contestants (with added 2, then 13, and by season six 14), each one more different than the other. Except Katie and Sadie, but that's their point.
- Lauren Faust has explicitly stated that she has designed the Mane 6 characters in My Little Pony: Friendship Is Magic to cover all the different personalities of girls.
Lauren Faust: There are lots of different ways to be a girl. You can be sweet and shy, or bold and physical. You can be silly and friendly, or reserved and studious. You can be strong and hard working, or artistic and beautiful. This show is wonderfully free of token girl syndrome, so there is no pressure to shove all the ideals of what we want our daughters to be into one package.