Life is tough for a wandering monster. Not only do you have to live in a dungeon with no new energy entering the ecosystem, but you're in constant danger of being killed by treasure hunters or perhaps other monsters. Can't be a fun existence.
But wait! The adventurers are in an environment just as dangerous, and they live a lot longer! They get all those nifty healing potions and shiny swords and glamorous quests! Their goodness feels good! People respect them... well, usually! They're at the top of the world! Well, to the thinking monster, a course of action suggests itself...
This trope is not for Mons, Pet Monstrosities, or Monster Allies. This is when a lone adventurer, an entire party, or at the very least a core party member are of a 'monsternote ' species. By definition either a Reluctant Monster or a Defector from Decadence, a Monster Adventurer might also be a Horrifying Hero depending on how monstrous they are. The civilian version is a Friendly Neighborhood Vampire.
Note that this trope only applies when there's an Always Chaotic Evil (or Always Neutral Hungry) morality for the Monster Adventurers to break free from, otherwise they're just normal adventurers of an unusual species. The Monster Adventurer's natural habitat is the RPG-Mechanics Verse, though they're also frequently found in settings with Loads and Loads of Races. See also Breakout Mook Character, My Species Doth Protest Too Much, Perspective Flip and Player Character.
- Marvel Comics' series Nick Fury's Howling Commandos (not the one set in WWII). Starring the likes of Warwolf, N'Kantu the Living Mummy, Frankenstein (a clone of the original Frankenstein's monster), Gorilla-Man, and a zombie named John Doe.
- Along similar lines and years earlier, DC Comics' Creature Commandos. Unlike the Howling Commandos, who were taken from a pool of supernatural creatures known to SHIELD, the original Creature Commandos were all normal humans at one point, deliberately transformed into monsters by scientific means for the purposes of psychological warfare.
- Dungeon Monstres #1 gives us the merry band of Juan-Juan (A Bogeyman fighter), Darmfloor (An Undead magician), Wilfried (An Elephant barbarian-monk), Yomanda (An Ochtone with no discernible class) and... Willem van Dattum (An evil salesman who bears the Sword of Destiny at the time).
- Dan Brereton's The Nocturnals features Doc Horror and his daughter Evening (a pair of pointy-eared alien refugees who have dealings with the Pacific City criminal underworld, with Doc being an ex-enforcer) and their crew of monstrous adventurers: Starfish (a fish-girl that belongs to an amphibious prehistoric race), Bandit (a mutant beastman crimeboss), Firelion (a Black-ops pyrokinetic former cop with an artificial fireproof body from a Mad Scientist group), Gunwitch (a zombie gunslinger) and Polychrome (a ghost girl). Together they often deal with supernatural threats to Pacific City and other areas of the United States, taking care not to be seen by the general public.
- Drizzt Do'Urden of the Forgotten Realms Legend of Drizzt books. His father Zaknafein might have become one, had he not fallen prey to Mentor Occupational Hazard.
- The Iron Teeth web serial features Blacknail the goblin as its protagonist. He is a goblin who is part of a group of human bandits. Together they attempt to survive in the hostile frontier of the Iron Teeth mountains.
- The War of the Spider Queen series is mostly about a bunch of drow on a quest to find out why their boss doesn't answer calls. They even took a Draegloth with them, and later sort of picked up an Alu-fiend. Of course, unlike Salvatore's most famous Drow protagonist, they're all evil.
- Paul Kidd's three contributions to the "Greyhawk Classics" — a set of seven Dungeons & Dragons novels based on famous adventure modules — all make use of this trope. Whilst the adventuring party is led by a human ranger called the Justicar and contains another human fighter, Henry, the rest of the party consists of: Escalla, a flamboyant pixie sorceress (the Justicar's lover, no less); Enid, a sheepish gynosphinx; Cinders, the soul of a redeemed hellhound bound into its own flayed pelt-turned-cloak; and Polk, a human merchant who died in one adventure and was reincarnated as a talking badger.
- Everybody Loves Large Chests revolves around a Mimic and its band of summoned demons, Plant People, and other monsters.
- Dungeons & Dragons always was ready to throw an occasional monster at least as a sidekick, eventually including just about everything. In fact, monster adventurers have been a thing in every single edition.
- Basic D&D had four "Creature Crucible" supplements covering an array of classic monsters (alongside nonhuman races native to Mystara, such as Nagpas and Tabi).
- The first, "Tall Tales of the Wee Folk", was all about classic fairies, such as brownies, redcaps, pixies, pookas, dryads, fauns/satyrs, leprechauns, and sprites, alongside both "D&D fae", like the centaur and treant, and Mystaran fae, like the Hsiao, Wood-Imps and Wooddrakes.
- The second, "Top Ballista", was about various flying monsters. Whilst more Mystaran-heavy than the first, it still included classic monsters like gremlins, harpies and sphinxes.
- The third, "The Sea Peoples", had sea giants, various flavors of mermaid and Fish People, nixies, and the Kopru — a sort of underwater Illithid equivalent.
- The fourth, "Night Howlers", covered all manner of werecreatures.
- Advanced D&D has "The Complete Book of Humanoids", mostly based on traditional Mook species, as well as an array of not normally evil but definitely not "demihuman" races.
- In 3e, this became a routine procedure. As mentioned in The Order of the Stick example, there are rules for monster NPCs, but most of the monster races aren't really that good as player characters. The reason for that is level adjustment. It means that to pay for the increased power of, say, being able to eat your opponents' brains and mindblast them, some of your levels don't actually count for the character's advancement, meaning you're perpetually between 2 (drow) and 6 (mindflayer) levels behind every other player character. While the abilities you gain are pretty cool, they're often no match for the increased Hit Points and especially spellcasting power actual levels would give you.
- The 3e D&D book Enemies and Allies (containing ready-to-use NPCs for various occasions) contained such a group of adventurers: a troll fighter (full plate but fights with claws), an ettercap cleric (rather smart for an ettercap but Int isn't his casting stat anyway), a pseudodragon sorcerer (ditto), a phase spider rogue (who needs lockpicks when you can pass through walls?), and an umber hulk monk (who fights blindfolded, purely by tremorsense, to protect his teammates from his gaze). A Ragtag Bunch of Misfits if ever there was one, but rather friendly if you don't attack right away.
- In 4e, with the NPC stats at the back of the first two Monster Manuals, playing a monster PC is more mechanically viable than ever. Many of these races were subsequently expanded upon and made stronger with articles in Dragon or appearing in sourcebooks. Notably, minotaurs became a playable race in the 3rd Player's Handbook, goblins and kobolds made the jump in the Dungeon Survival Handbook, revenants, shades and vrylokas (a kind of living vampire) appeared in Heroes of the Shadowfell, and Dragon was home to playable stats for gnolls, shadar-kai, kenku, draconians, hobgoblins and bladelings, amongst others.
- Mystara had its 10th "Known World Gazetteer" be "The Orcs of Thar", which was all about both a kingdom of traditional "monstrous humanoids" (orcs, goblinoids, gnolls, trolls, ogres, kobolds) and rules for creating and playing such beings.
- Spelljammer, aside from its vast array of Intelligent Gerbil races, has one such race: the Scro, a sort of Nazi-esque "super orc" species normally painted in the hostile role in the setting.
- It also has a classic NPC illithid who hires the party in one adventure and is a major character of the Cloakmaster cycle. Estriss had nothing against other mindflayers in general, it just didn't allow their boring universal domination plans to interfere with more important things, such as its own quest for an ancient mystery.
- Forgotten Realms, from AD&D1e times had the Mindulgulph mercenary company, which was mostly non-humanoid. Named after a ruined castle that one warrior lady turned into her base mainly through use of telepathic communication first on everything moving during a dungeon crawl.
- The Dark Sun setting includes the Thri-Kreen — anthropophagous mantis warriors — as player characters from the get-go, with further expansions providing at least six different Kreen sub-species. In its Revised edition, it added the Pterrans, a sort of neo-Lizard Folk race.
- Planescape had quite a bit of this and was a bit more open to it than most other D&D settings since it subverted the typical good vs evil dynamic in favor of a more political approach to everything. Initial rules allowed players to select tieflings (humans with some fiendish ancestry) and baurier (centaur-like humanoids with the lower bodies of bighorn sheep instead of horses) while later supplements added races like bladelings (tall humanoids who were covered in spikes), aasimar (humans with celestial ancestors), and rogue modrons (cube-shaped beings from the plane of Law who either had wings or an extra pair of arms).
- Dragonlance is mostly remembered for its Tinker Gnomes and Kender, but it actually featured Minotaurs as a playable race literally from the start, with the release of "Dragonlance Adventures" for AD&D 1st edition. In 3rd edition, its iconic Draconian race also joined the playable race list.
- 5e features the supplement Volo's Guide To Monsters, which includes player character templates for some monster races, such as goblins, hobgoblins, kobolds, orcs, yuan-ti, etc. All of these are roughly on par with other playable races so as to prevent punishing level adjustments (although the yuan-ti is an obscene Game-Breaker with permanent Anti-Magic and innate access to the powerful Suggestion spell).
- Basic D&D had four "Creature Crucible" supplements covering an array of classic monsters (alongside nonhuman races native to Mystara, such as Nagpas and Tabi).
- Pathfinder overtly tries to avert this trope, emphasizing the Always Chaotic Evil nature of its monsters, but at the same time includes a wide variety of monster races, complete with rules for playing them in the Monster Manual. Unlike its ancestor, D&D, it does emphasize that more levels will ultimately outweigh the front-loaded initial benefits of monster-hood, and recommends slowly moving the player's level into sync with the rest of the party's over time. The book Advanced Race Guide adds many options to make this more viable/fun, including a race builder (though a large part of the book is still dedicated to the core races).
- Several NPCs in Mabinogi are monstrous humanoids, like Elatha the incubus. There's also the option of playing as one of your pets, so Pet Monstrosities like spiders or vipers might count.
- Neverwinter Nights. The Badlands servers allow you to choose from more than 60 monster types to use as your character's race.
- Among the many playable races in Dungeon Crawl are kobolds, mummies, ghouls, and orcs, the last of which can even get other orcs to follow him/her as their messiah.
- Disgaea offers your entire cast as demons or angels, and you can get every single monster species you find and equip them with weapons AND armor. Then again, it's Hell.
- World of Warcraft: Horde player characters are all about this, with the Horde representing a goodish-neutral version of the Fantasy Axis of Evil — orcs, trolls, undead, "minotaurs" (Tauren). The expansions mix up this pattern when adding new races to both sides, with for example werewolves (Worgen) going on the Alliance side.
- The Charr of Guild Wars 2 are this to those who played the original Guild Wars, where they were evil and man-eating (which was actually propaganda); after dethroning the zealots using a false religion to guide them, they're now in an uneasy truce with the humans to fight their common foe, the dragons, and wander the world to that end.
- In the second game of the SaGa series, your entire party (Main character included) can be monsters. The third game starts all of your characters off as human, but allows them to become monsters.
- Gobli's Adventure, the sample game that came with the original Playstation RPG Maker tool starts with an A.I. controlled party slaughtering goblins. After respawning, Gobli decides that he'd rather be an adventurer than XP fodder, and sets out on a quest to do so. He is joined by a literal hole in the wall that wants to become an NPC and a kitten that wants to be a Final Boss.
- The Dragonborn in The Elder Scrolls V: Skyrim is a somewhat example, being a Dragon in human/oid form. Dragons in this setting are innately driven to destroy and dominate others, something that even the reformed dragon Paarthurnax admits he struggles with. He notes that with their kinship, those same urges are present in the Dragonborn as well.
- The Dragonborn can take this trope to ridiculous levels. S/he can be a cat/lizard man who can transform into a daedric (read: demonic) created vampire/werewolf.
- The Companions in the same game as well, due to being essentially an adventurer's guild of werewolves.
- The Libra of Soul's Featureless Protagonist in Soulcalibur VI can potentially qualify as this if they belong to an inhuman race such as Lizardmen, Mummies, Malfested, Lost Souls or Malefic.
- There's a passing mention in The Order of the Stick: Start of Darkness.
Dark One: You made us and the humans, but they get to be PC races while we are slaughtered by adventurers?
Marduk: Well, there are those rules for monster PCs—
Dark One: Those rules are crap and you know it!
- Later Malack turns out to be a vampire, which has a punishing level adjustment of eight, was previously part of an adventuring party, and notes that the level adjustment suffered in a Dungeons & Dragons world does make it difficult to find "appropriate" challenges to level up on.
- Xykon, as a lich, has a level adjustment of four, although it doesn't seem to impede him nearly as much as the one above despite being into epic levels even before the adjustment is calculated. As the primary villain of the comic he may benefit from accelerated XP growth to keep him outmatching the heroes though.
- As featured in the picture, the core cast of Rusty and Co. consists of a fast-talking mimic, a rust monster, and the silent-but-deadly Gelatinous Cube, plus usually an Action Girl from a rotating Guest-Star Party Member roster.
- The party is made up of goblins whose village was destroyed but realized they could better defend their tribe by leveling up. The Hero Antagonists now also travel with a yuan-ti, and there's a deuteragonist dungeon party made up of three goblins, a lizardfolk/ogre hybrid, and a weird flying, shapeshifting metal thing called Klik.
- The lizardfolk was horrified when he learned one of the goblins only beat him because she took adventurer levels, something he considers to be cheating.
- The party in Slightly Damned includes the fire demon Buwaro — who, by the way, is an incredibly nice guy.
- Yet Another Fantasy Gamer Comic plays with it. Just look at its article's page picture. It started with beholders, kobolds and harpies, continued with a lich and drow, and most of the time retains at least a token mongrelman even when it mainly involves more traditional PC races. Sometimes Always Chaotic Evil aren't very chaotic or evil, sometimes they very much are, and sometimes they have a reason to team up with "good" guys.
- The eponymous anti-hero party of Anti-Heroes is composed of a vampire, a ghost, a tiefling, and a half-demonic (or is it half-divine?) mysterious cloaked figure. They are also much more sympathetic than the nominally "hero" party including more standard races.
- By the Book is about a party consisting of a goblin, an orc, and a kobold. Later they're joined by some humans and a tiefling. And their "former" employer sent a group consisting of a couple goblins, a hobgoblin, a half-orc-half-ogre, and a gnoll to retrieve them, who have gotten somewhat sidetracked by a series of unstable portals.
- Unsounded: Duane may have been blackmailed into guarding Sette as they trek across the continent at first, but he seems to be genuinely enjoying it.
- Dan from Dan and Mab's Furry Adventures is an incubus and retired adventurer; however, he was never both at the same time. His cubi-based powers didn't manifest until after he quit adventuring, so during that time, he was just an adventurer with wings; and is now an incubus with adventuring skills.
- Awful Hospital: Everyone who joins up with Fern as companions.
- Monsters Can Be Heroes Too!: which centers on Coal the Kobold trying to become a hero... and not being 100% as to how. She ends up recruiting a slime named Lime (Coal was sent to go kill a slime but ended up bringing it back with her) and a White Mage skeleton named Shelley (who worked for an evil skeleton gang before accidentally killing one of them with healing magic).