Monsters: O
47 monsters whose names start with O.
- Oathbinder Genie [Tasked] A black-skinned efreeti wreathed in white flame that exists only to enforce sworn oaths, appearing within moments of a broken vow to burn the oathbreaker and imprison their ghost.
- Oathkeeper Fiend [Lesser Mercenary] Lopsided, red-scaled petty lords of the mercenary fiends, with one giant arm that stuns, acid breath, and a hunger for the life force of unconscious foes.
- Obedient Ordinary townsfolk hypnotized into lifelong service, the Obedient watch every stranger in a genteel southern domain and quietly report, poison or ambush on their master's behalf.
- Obliviax A glossy black moss that steals a day's memories and spells from passersby, then grows tiny moss copies of its victims that hurl their own stolen magic back at them.
- Obsidian Figurine A jagged little ape of fused volcanic glass that slashes in a frenzy, may carry poison or snapping spines, and sprays razor shards whenever someone strikes it.
- Obsidian Retriever [Dark Sun] A spider-shaped golem of black volcanic glass that guards ancient treasures, hurls elemental spells from its eyes, and tirelessly tracks down any thief who escapes it.
- Octo-Jelly A blind, bell-shaped deep-sea octopus that drops over prey like a living sack, chewing and smothering it, then blinds stronger foes with a glowing cloud.
- Odem An invisible evil spirit that slips into a living person through the mouth or ear and rides them like a puppet, sowing hatred while its host watches helplessly.
- Odontogriphus A flat, leech-like swimmer that glides like a ray, drops onto prey with a ring of teeth, and can wrap around a victim to drink and smother at once.
- Ogre Hulking, foul-smelling raiders who sell their muscle to orcs and evil priests, hoard every coin they can grab, and count elves, dwarves and halflings as dinner.
- Ogre [Al-Qadim] In the desert lands ogres are not raiders but respected citizens, groomed, perfumed and honorable, prized as soldiers and laborers while they hunt their own brutish half-mage kin.
- Ogre [Dragonlance] Filthy, lice-ridden brutes descended from a once-beautiful elder race, these ogres kill strangers on sight, slay their own elderly, and torture tribal criminals for sport.
- Ogre Giant Shaggy, elephant-eared brutes twenty feet tall, ogre giants lob two boulders a round, guard reclusive masters, and fly into destructive rages when crowds or lies confuse them.
- Omm-wa Gentle, manatee-like water-people who farm underwater fields, write in pebbles and knotted beads, and follow a matriarchy whose males die gladly defending the herd.
- Omshirim A mage-bred quicksilver predator that poses as a glittering vein of precious ore, then leaps out to wrap and suffocate anyone greedy enough to come close.
- Onco A bear-sized jungle elephant with a foul temper, short tusks of unusually strong ivory, and a habit of driving every other creature out of its patch of forest.
- Ondonti [Orc] Gentle, orc-like farmers devoted to a goddess of peace, now hunted and enslaved by a wizard cabal that hopes to breed them into a perfect army.
- Oni Hulking, horned spirit-brutes of the east who shapeshift, fly and turn invisible to waylay travelers, carouse with flutes after a kill, and serve heaven's armies in their mightiest forms.
- Ontalak [Plasmoid] A colossal plasmoid that disguises itself as a derelict starship, a haunted house or a ghost ship, waiting for curious looters to step aboard its digestive hull.
- Onyx Dragon [Mystara] A stealthy swamp gem dragon whose acid breath can wrap a victim in moving magical darkness that only the dragon can see through.
- Oortling Pallid, big-brained comet dwellers bred like cattle by mind reavers, a once-gifted people now too broken to do more than cower until they are eaten.
- Ooze Sprite A quiet heap of sentient muck from the plane of Ooze that bends minds with a single slimy touch, and may be pulling far more strings than anyone suspects.
- Ooze/Slime/Jelly I Olive slime that turns its hosts into plant zombies, a cursed mustard jelly that splits and slows its prey, and a stunjelly disguised as a dungeon wall.
- Ooze/Slime/Jelly II The classic dungeon scavengers: the splitting ochre jelly, metal-eating gray ooze, near-invisible crystal ooze, paralyzing gelatinous cube and flesh-converting green slime.
- Opabinia A five-eyed prehistoric sea predator that lies camouflaged on the seabed, then snaps out a long clawed trunk to haul swimmers under and drown them.
- Ophidian Snake-bodied ambushers with human arms and a venomous bite that slowly turns its victims into new snakemen, stripping away their memories scale by scale.
- Opinicus A prankish, camel-bodied desert guardian with eagle wings and a monkey's face, whose clerical magic, psionics and sun-bright gaze make it a terror to undead.
- Opposition A contrary planar sect of fighters who believe struggle makes everything stronger, so they resist everyone and everything, including each other and their own creed.
- Orange Dragon [Sodium] A blazing-hued jungle tyrant descended from red dragons, equally happy to roar a challenge or spring from ambush, and quick to bully black dragons out of its swamps.
- Orc Tusked, pig-snouted raiders who live for war and territory, and whose tribes are far cannier tacticians than their reputation for mindless brutality suggests.
- Oread Stone-skinned mountain spirits who guard their peaks with charming songs, stone-melding ambushes and, among their eldest, a petrifying touch for persistent miners.
- Orglash [Ice Spirit] Fickle little whirlwinds of snow and razor ice that guard the peaks of a cold eastern land, tearing apart foreign invaders and sometimes the locals too.
- Oriental Dragon Overview The wingless dragons of eastern lands are spirit-officials of a heavenly court, mind-reading, invisible at will, and flying by the power of magical pearls set in their skulls.
- Oriental Vampire A faintly glowing eastern vampire with foot-long razor nails that walks through walls, fades from sight, becomes a tiger, and treats mortals as nothing more than cattle.
- Ormyrr Four-armed, frog-headed worm warriors from the northern lakes who hurl boulders, constrict their foes, and crave any magic that might finally let them fly.
- Orog [Birthright] Gray-skinned, apish mountain warriors who wage endless war from hidden underground holds, riding giant lizards and shunning the sunlight that blinds them.
- Orpsu Legless, jawless 'night stirges' that freeze prey with a paralyzing glance, slash past on blade-like bone horns, then settle on the helpless to drink.
- Orrumvast [Unique Bronze Dragon] An old bronze dragon who has guarded a port city's treasury for fifty years at ten gold a day, slowly and with perfect honesty, bankrupting the city that hired him.
- Osquip [Rat] A hairless, many-legged rodent the size of a dog, the osquip chews tunnels through solid stone beneath cellars and dungeons and erupts from hidden holes to savage intruders.
- Osyluth [Lesser Baatezu] Skeletal, scorpion-tailed enforcers of infernal law, osyluths may punish devils far above their own rank, which makes them both feared and quietly murdered whenever possible.
- Ottoia A buried prehistoric worm that lurks in sandy pits, shooting out a fanged proboscis to bite or swallow whole anyone who steps too close.
- Otyugh Filth-dwelling, three-legged garbage eaters with grasping tentacles and disease-laden bites, who trade guard duty to dungeon neighbors in exchange for their waste.
- Ouija Table An ordinary-looking table soaked in years of desperate seances that has quietly woken, and now twists every reading and curses those who consult it.
- Overseer Fiend [Lesser Mercenary] Lobster-bodied, limb-severing sergeants who whip companies of lesser mercenary fiends into line, summon reinforcements at will, and poison foes with their mouth tentacles.
- Owl Silent night hunters with uncanny eyes and ears, from ordinary barn owls to intelligent giant owls and rare talking owls that guide heroes on good quests.
- Owlbear I A furious, feathered hybrid of bear and giant owl that attacks anything on sight, crushes victims in a bone-breaking hug and never retreats.
- Owlbear II Two rarer owlbear breeds: a snow-white arctic hunter that swims after prey through icy water, and a winged terror that strikes silently from the sky.