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The Complete List of Animals That Start With O

This list includes 45 Animals that start with O, from “Oarfish” to “Oystercatcher”. It covers species from deep-sea fish to coastal birds and land mammals. You can use it for quick reference, teaching, or classroom activities.

Animals that start with O are a diverse group spanning fish, birds, mammals, reptiles, and invertebrates. The giant oarfish helped inspire sea‑serpent legends in coastal folklore.

Below you’ll find the table with Common name, Scientific name, Habitat, Region, Description, and Conservation status.

Common name: The everyday English name used to identify the species quickly and match common references.

Scientific name: The Latin binomial that uniquely identifies the species across languages and scientific lists.

Habitat: The typical biome or environment where the species lives, helping you understand its ecological niche.

Region: The geographic area or range where the species occurs, so you can link it to places you know.

Description: A concise one or two sentence summary of appearance, behavior, or notable traits for quick context.

Conservation status: Current threat category (for example, Least Concern or Endangered) that shows conservation priority.

Animals that start with O

NameScientific nameHabitat (biome + region)Conservation status
OcelotLeopardus pardalistropical rainforest — Central & South AmericaLC
OrcaOrcinus orcapelagic ocean — worldwideDD
OstrichStruthio camelussavanna — AfricaLC
Olive ridley sea turtleLepidochelys olivaceatropical ocean — Indian, Pacific & Atlantic OceansVU
Orange roughyHoplostethus atlanticusdeep sea — temperate oceans worldwideVU
OspreyPandion haliaetuscoastal wetlands & rivers — worldwide (except polar regions)LC
OilbirdSteatornis caripensistropical rainforest caves — northern South AmericaLC
OpahLampris guttatuspelagic ocean — temperate & tropical oceans worldwideLC
OlmProteus anguinussubterranean freshwater caves — Dinaric Alps (Europe)VU
OvenbirdSeiurus aurocapillatemperate forest understory — North AmericaLC
Ocellated turkeyMeleagris ocellatatropical dry & moist forest — Yucatán PeninsulaNT
OrangutanPongo (genus)tropical rainforest — Borneo & SumatraEN (varies by species)
Ocean sunfishMola molapelagic marine — temperate & tropical oceans worldwideVU
Oceanic whitetip sharkCarcharhinus longimanusopen tropical oceans — worldwideCR
OystercatcherHaematopus ostraleguscoastal mudflats & sandy shores — Europe, Asia & AfricaLC
OnagerEquus hemionusarid steppes & deserts — Central Asia & Middle EastEN
OxpeckerBuphagus (genus)savanna & grassland — Sub-Saharan AfricaLC (varies)
Olive baboonPapio anubissavanna & woodland — AfricaLC
Owlet-nightjarAegotheles cristatuswoodland & forest — AustraliaLC
OctopusOctopus (genus)coastal reefs & seafloor — worldwide temperate & tropical seasNot Evaluated
OysterOstreidae (family)intertidal estuaries & bays — worldwideNot Evaluated
Ochre sea starOreaster reticulatusshallow tropical marine — Caribbean & western AtlanticNot Evaluated
Oyster toadfishOpsanus tauestuaries & bays — western Atlantic (North America)LC
Orange-bellied parrotNeophema chrysogastercoastal saltmarsh — southeastern AustraliaCR
OribiOurebia ourebigrassland & open savanna — Sub-Saharan AfricaLC
Ocellated lizardTimon lepidusMediterranean scrub & rocky habitats — Iberian Peninsula & NW AfricaLC
OarfishRegalecus glesnemesopelagic ocean — temperate & tropical oceans worldwideNot Evaluated
Orchid mantisHymenopus coronatustropical rainforest — Southeast AsiaNot Evaluated
Ocellaris clownfishAmphiprion ocellariscoral reefs — Indo-PacificLC
Oriental scops owlOtus suniaforests & woodland — South & Southeast AsiaLC
One-horned rhinocerosRhinoceros unicornisgrasslands & riverine forest — Indian subcontinentVU
Oceanic mantaMobula birostrispelagic tropical & subtropical oceans — worldwideEN
OlinguitoBassaricyon neblinamontane cloud forest — Andes (Colombia, Ecuador)LC
Orange-footed scrubfowlMegapodius reinwardtrainforest edge & mangroves — Australia & New GuineaLC
Oriental garden lizardCalotes versicolorscrub, forest edge & urban gardens — South & Southeast AsiaLC
OrioleIcterus (genus)woodland & forest edge — AmericasLC (varies)
Olive-backed sunbirdCinnyris jugularistropical forest edge & gardens — Southeast Asia & AustralasiaLC
Olive pythonLiasis olivaceusarid woodlands & rocky gorges — AustraliaLC
Oriental pratincoleGlareola maldivarumfreshwater wetlands & open grasslands — Asia & AustraliaLC
Oriental cockroachBlatta orientalisurban & temperate habitats — cosmopolitan (originally Palearctic)Not Evaluated
Oriental magpie-robinCopsychus saulariswoodland & urban gardens — South & Southeast AsiaLC
OpaleyeGirella nigricansrocky reefs & kelp beds — eastern Pacific (California to Mexico)LC
Oriental darterAnhinga melanogasterfreshwater wetlands & marshes — South & Southeast AsiaNT
Orchard orioleIcterus spuriustemperate woodlands & orchards — North AmericaLC
Oriental small-clawed otterAonyx cinereusfreshwater rivers & mangroves — South & Southeast AsiaVU

Descriptions

Ocelot

Ocelot

A medium-sized spotted wild cat that hunts at night, agile in trees and on the ground, important predator in Neotropical ecosystems.

Orca

Orca

A highly social, intelligent dolphin known as the killer whale, striking black-and-white pattern, apex predator with diverse regional populations and diets.

Ostrich

Ostrich

The world’s largest bird, flightless and built for running, with powerful legs and distinctive feathers; adapted to open, dry grasslands.

Olive ridley sea turtle

Olive ridley sea turtle

A small, sociable sea turtle famous for synchronized mass nesting (“arribadas”); threatened by nets, habitat loss and egg collecting.

Orange roughy

Orange roughy

A slow-growing, long-lived deepwater fish targeted by fisheries; vulnerable to overfishing because populations recover very slowly.

Osprey

Osprey

A fish-eating raptor with reversible outer toes and striking diving behavior; nests near water and is familiar across continents.

Oilbird

Oilbird

A nocturnal, fruit-eating bird that navigates by echolocation in caves, unique among birds for its cave-roosting lifestyle.

Opah

Opah

A large, round-bodied, warm-blooded pelagic fish often seen near the surface; notable for its bright coloration and deep-sea migrations.

Olm

Olm

A pale, blind cave salamander with extreme adaptations to dark groundwater systems, living decades and sensitive to water pollution.

Ovenbird

Ovenbird

A ground-dwelling warbler named for its oven-shaped nest; migratory and known for loud, ringing song in eastern forests.

Ocellated turkey

Ocellated turkey

A colorful wild turkey with iridescent plumage and eye-like wing spots, endemic to the Yucatán and vulnerable to habitat loss and hunting.

Orangutan

Orangutan

Great apes with long arms, tree-dwelling intelligence, and slow reproduction; species face severe habitat loss and hunting in Southeast Asia.

Ocean sunfish

Ocean sunfish

A massive, flattened fish known for its odd shape and surface basking; feeds on jellyfish and is vulnerable to bycatch and boat strikes.

Oceanic whitetip shark

Oceanic whitetip shark

A once-abundant pelagic shark recognizable by long white-tipped fins; populations plummeted due to longline fisheries and finning.

Oystercatcher

Oystercatcher

A stout shorebird with a strong, chisel-like bill used to pry bivalves and worms from intertidal habitats.

Onager

Onager

A wild Asiatic ass adapted to hot, open habitats; historically widespread but now reduced by hunting and habitat fragmentation.

Oxpecker

Oxpecker

Birds that perch on large mammals to feed on ticks and parasites, exhibiting a mutualistic yet sometimes parasitic relationship.

Olive baboon

Olive baboon

A highly social primate with complex hierarchies, opportunistic omnivore, common across many African habitats and familiar near human settlements.

Owlet-nightjar

Owlet-nightjar

A small, insectivorous nocturnal bird with a flattened head and cryptic plumage, roosting in tree hollows by day.

Octopus

Octopus

Flexible, highly intelligent cephalopods known for problem-solving, camouflage, and complex behaviors; species-level statuses vary widely.

Oyster

Oyster

Bivalve mollusks that filter water and form reefs, vital to coastal ecosystems and fisheries; many species face local pressures.

Ochre sea star

Ochre sea star

A large, colorful starfish of sandy and seagrass habitats, often seen in Caribbean shallow waters; local impacts from collection exist.

Oyster toadfish

Oyster toadfish

A stout, well-camouflaged bottom-dweller that produces grunting sounds and tolerates low-oxygen brackish waters.

Orange-bellied parrot

Orange-bellied parrot

A tiny migratory parrot with vivid belly color, critically endangered due to habitat loss and small wild population size.

Oribi

Oribi

A small, graceful antelope of open habitats that feeds mainly on grasses and relies on speed and agility to avoid predators.

Ocellated lizard

Ocellated lizard

A large, eye-spotted lacertid lizard common on sunny rocky slopes and scrubland in southwestern Europe.

Oarfish

Oarfish

A very long, ribbon-like deepwater fish often washed ashore; rare sightings inspire myths about sea serpents.

Orchid mantis

Orchid mantis

A striking praying mantis that mimics orchid flowers to ambush pollinating insects; prized by insect enthusiasts.

Ocellaris clownfish

Ocellaris clownfish

A small, colorful reef fish living in anemones and popular in aquaria; forms symbiotic relationships with its host anemone.

Oriental scops owl

Oriental scops owl

A small, camouflaged owl with ear tufts that hunts insects and small vertebrates at night across Asian woodlands.

One-horned rhinoceros

One-horned rhinoceros

A large, thick-skinned herbivore with a single horn, reliant on floodplain grasslands and protected by intensive conservation efforts.

Oceanic manta

Oceanic manta

A giant filter-feeding ray with broad pectoral fins and a suspension-feeding diet, threatened by bycatch and targeted fisheries.

Olinguito

Olinguito

A small, nocturnal carnivoran discovered recently; tree-dwelling and frugivorous, indicative of intact cloud-forest habitat.

Orange-footed scrubfowl

Orange-footed scrubfowl

A mound-building bird that incubates eggs with warm decomposing vegetation; common in coastal forested habitats.

Oriental garden lizard

Oriental garden lizard

A common, adaptable lizard often seen basking on trees and walls, able to change some coloration with mood and season.

Oriole

Oriole

Brightly colored passerines known for melodious songs; many species called orioles inhabit New World forests and gardens.

Olive-backed sunbird

Olive-backed sunbird

A small, nectar-feeding bird with metallic throat in males, frequent in gardens and coastal forests.

Olive python

Olive python

A large nonvenomous constrictor with olive-brown coloration that preys on mammals and birds in northern and western Australia.

Oriental pratincole

Oriental pratincole

A slender, aerial insectivore that nests on the ground and performs acrobatic flight to catch flying insects.

Oriental cockroach

Oriental cockroach

A widespread synanthropic roach species common in cool, damp human environments; considered a pest in many regions.

Oriental magpie-robin

Oriental magpie-robin

A familiar songbird with melodious calls, adaptable to gardens and parks, often tolerant of human presence.

Opaleye

Opaleye

A dusky, broad-bodied fish that grazes algae on rocky reefs, common along temperate Pacific coasts.

Oriental darter

Oriental darter

A fish-eating waterbird with a long, snake-like neck that swims low in the water; local populations face wetland loss.

Orchard oriole

Orchard oriole

A small migratory black-and-orange oriole that favors open woodland edges and orchards during the breeding season.

Oriental small-clawed otter

Oriental small-clawed otter

The smallest otter species, social and dexterous with partially webbed feet, threatened by habitat degradation and the pet trade.

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