The fauna of the world of Eamon is as diverse as the source material from which the Eamon adventures are drawn. Creatures of Star Wars fame, beings from The Hobbit, and seemingly half the bestiary of the Dungeons & Dragons franchise make appearances alongside more familiar real-world species. This makes a precise summary of the nature of Eamon impossible; nevertheless, a number of adventure authors describe some of the noteworthy beasts native to the planet Eamon.
One adventure that gives much detail concerning the native fauna of the planet Eamon is Rick Volberding's Museum of Unnatural History. Part of the conceit of the adventure is that the creatures in the exhibits of the museum come to life to attack the adventurer, indirectly providing an account of Eamon's native wildlife. Beyond the more "mundane" inhabitants of Eamon—"mundane" including dinosaurs, frogs, or giant sloths—a more idiosyncratic menagerie is detailed.
|Bounder||The bounder is described merely as a "moderate-sized animal" which is able to reduce its weight by eating "ores".||Museum of Unnatural History|
|Carrion Crawler||A tentacled, centipede-like scavenger that feeds on carrion and other debris.||Castle of Doom|
|Cruscrunch||A "mouth-watering" black fish that one can catch in a lake with a fishing pole.||Wrenhold's Secret Vigil|
|Cute and Cuddly||The "cute and cuddly" (abbreviated as "cc") is described as "exud[ing] an aura of real-niceness" despite sporting fangs, claws, and a spiked tail. Its range is on the continent occupied by the Main Hall.||Museum of Unnatural History|
|Dragon||This powerful reptilian creature features in many adventures and has a variety of forms, some winged, some capable of breathing fire, and some intelligent and capable of speech.||Various|
|Eamonian Dust Mole||This rare creature the subject of a folk tale that says encountering an Eamonian dust mole is a foreboding omen, indicating that one is soon to die.||The Underground City|
|Floater||The floater is described as resembling Medusa, with a bloated mass floating mid-air from which tentacles devoted to propelling the creature are suspended. Its diet consists of "ores".||Museum of Unnatural History|
|Gurn||Two enormous gurns are encountered in the adventure: a juvenile gurn—described as "only" twelve feet tall—and a larger mother. It is also relayed that the gurn eats plants and that its young are covered in thick, blue fur.||Blood Feud|
|Hill Climber||A "weird animal with two short front legs and two longer hind legs." The hill climber is rare, and hence both living and dead specimens are worth a great deal.||Alternate Beginners Cave|
|Invisimal||The invisimal is described as an invisible, underground animal. Its ferocious demeanor suggests that the invisimal is a predator.||Museum of Unnatural History|
|Kzork||A creature capable of eating metal.||Eamon Adventurer's Log|
|Lama||Nathan Segerlind—in typical, humorous fashion—describes a ferocious (and "evil") creature indigenous to Eamon called a "lama," physically identical to the llama native to South America. (The player is cautioned in the description: "No, not a 'llama', llamas live in South America, not Eamon.")||The Lair of Mr. Ed|
|Mud-Lobber Wasp||The mud-lobber wasp is large in size — five feet in length — and is capable of attacking by casting a "gooey, black material".||Alternate Beginners Cave|
|Oreigan||A rare bird, now extinct. Blue and orange in color, they were once thought to be the pets of the gods and a feather from one of them was supposed to bring good luck.||The Prince's Tavern|
|Sinker||The sinker, like a Portuguese man o' war, consists of a mass floating above the water of lagoons. Unlike the man o' war, the sinker has a tail that it uses to spear fish for food. Though primarily an aquatic creature, the creature is able to "waddle" upon land as well.||Museum of Unnatural History|
|Slobovian Book-Eater||The Slobovian Book-Eater is a riff on the "Slobbovian Amp-Eater" from the the Lil' Abner comic strips. It is described as powerful enough to rip a door from its hinges and as having a literally omnivorous diet, though it prefers to eat books.||Enhanced Beginner's Cave|
|Snogglebeast||"A creature with the body of a bear and head of a tiger".||The Underground City|
|Swing-jaw||A species of fish that one might catch in a lake with a fishing pole.||Wrenhold's Secret Vigil|
|U-Goat||Beyond the standard features of a goat, the U-goat is described as featuring "U"-shaped horns and a big belly. It is native to the "horseshoe continent" of Eamon, a land whose other inhabitants similarly sport "U"-shaped horns.||Museum of Unnatural History|
|Venusian Metal Eater||The only information about the Venusian metal eater given in the adventure is that it possesses four rows of sharp teeth.||The Underground City|
In addition to many strange and wonderful species, Eamon is inhabited by a range of common forms of life that live on Earth, including terrestrial species such as horses, dogs, rats, pigs, frogs, sloths, and (in ages past) dinosaurs.