Animals that Start with O

Updated: October 11, 2022
© Svetlana Orusova/Shutterstock.com
Share on:

Advertisement


Read below for information on 66 different animals that start with the letter O, from ocelot to oyster. The most popular animal that starts with the letter O is the ocelot, a small cat also known as the painted leopard. The least popular O animal is the orangutan. Some can grow to be up to 200lbs, making them one of the largest primates in the world. Some fun facts about letter O name animals are:


Jump to any letter


Watch on YouTube

Alphabetical List of Animals That Start with O

Animals that Start with O

Oak Toad

Oak Toad Picture
Kingdom
Animalia
Phylum
Chordata
Class
Amphibia
Order
Anura
Family
Bufonidae
Genus
Anaxyrus
Scientific Name
Anaxyrus quercicus

Fun Fact: The toad doesn't hop.

Oak toads are the smallest of the toad species in North America, easily identified by a mid-dorsal, light stripe with variable black and brown spots. They have proportionally large parotoid glands. Most toads have that distinctive round vocal sound. The calling oak toad male has an elongated vocal sac. It extends significantly as they produce […] Read More


Oarfish

Oarfish Picture
Kingdom
Animalia
Phylum
Chordata
Class
Actinopterygii
Order
Lampriformes
Family
Regalecidae
Genus
Regalecus
Scientific Name
Regalecus glesne

Fun Fact: The Giant oarfish (Regalecus glesne) holds the Guinness Book of World Records for the longest bony fish in the world.

The Giant oarfish (Regalecus glesne) holds the Guinness Book of World Records for the longest bony fish in the world. They are found in the depths of the Mediterranean sea and the eastern Atlantic Ocean and have a ribbon-like appearance. Oarfish are members of the Refalecidae family and are also known as the King of […] Read More


Ocean Perch

Ocean Perch Picture
Kingdom
Animalia
Phylum
Chordata
Class
Actinopterygii
Order
Scorpaeniformes
Family
Scorpaenidae
Genus
Sebastes
Scientific Name
Sebastes alutus

Fun Fact: As a scorpionfish, the ocean perch has spines along its back!

Summary The ocean perch (Sebastes alutus) is a commercially important fish in the North Pacific. It ranges along the Pacific coasts of the United States, Canada, Japan, and Russia. Distinguishing marks of this moderately-sized marine species include a reddish body and dorsal spines. They are deepwater bottom-dwellers, living at depths up to 2,700 feet. 5 […] Read More


Ocean Pout

Ocean Pout Picture
Kingdom
Animalia
Phylum
Chordata
Class
Actinopterygii
Order
Scorpaeniformes
Family
Zoarcidae
Genus
Zoarces
Scientific Name
Zoarces americanus

Fun Fact: Females guard their eggs for up to 3 months

Zoarces americanus belongs to the eelpout family Zoarcidae. You can find this large eelpout species throughout the northwest Atlantic Ocean. It is a predatory bottom feeder that lives at a wide range of depths. Its blood possesses an antifreeze protein that enables it to withstand frigid waters. Although commercial fisheries don’t regularly harvest them, the […] Read More


Ocean Whitefish

Ocean Whitefish Picture
Kingdom
Animalia
Phylum
Chordata
Class
Actinopterygii
Order
Perciformes
Family
Malacanthidae
Genus
Caulolatilus
Scientific Name
Caulolatilus princeps

Fun Fact: Common around Southern California

Summary A staple in Southern California, the ocean whitefish is a member of the tilefish family Malacanthidae. While commonly caught as bycatch, ocean whitefish aren’t actively targeted by most commercial fisheries in the United States. They are highly active and mostly solitary outside of the spawning and mating season. During the day, they come to […] Read More


Oceanic Whitetip Shark

Oceanic Whitetip Shark Picture
Kingdom
Animalia
Phylum
Chordata
Class
Chondrichthyes
Order
Carcharhiniformes
Family
Carcharhinidae
Genus
Carcharhinus
Scientific Name
C. longimanus

Fun Fact:

Unlike most sharks, the oceanic whitetip shark is known for being opportunistic and aggressive. The oceanic whitetip shark is a critically endangered species that inhabit tropical waters. They have white tips on their fins, hence the species’ name. 5 Oceanic Whitetip Shark Facts Aggressive: Unlike most sharks, many experts consider this species aggressive. As opportunistic […] Read More


Ocellated Turkey

Ocellated Turkey Picture
Kingdom
Animalia
Phylum
Chordata
Class
Aves
Order
Galliformes
Family
Phasianidae
Genus
Meleagris
Scientific Name
Meleagris ocellata

Fun Fact: These birds are timid and hard to spot, but their noisy gobbles give them away.

“Its specific name, ocellata, refers to the spots, or ocelli, on their tail feathers.” Summary The ocellated turkey (Meleagris ocellata) is endemic to the Yucatán Peninsula and parts of Belize and Guatemala. These birds are somewhat elusive and hard to catch, but they are noisy with distinctive gobbles. They live in tropical and evergreen forests, […] Read More


Ocelot

Ocelot Picture
Kingdom
Animalia
Phylum
Chordata
Class
Mammalia
Order
Carnivora
Family
Felidae
Genus
Leopardus
Scientific Name
Leopardus pardalis

Fun Fact: Also known as the Painted Leopard!

Classification and Evolution The Ocelot is a medium-sized small cat that is native to the jungles of South America. The Ocelot is also known as the Painted Leopard due to the beautifully distinctive markings on its fur as it displays dark rosettes, along with spots and stripes. Similar in coloration to the much smaller but […] Read More


Octopus

Octopus Picture
Kingdom
Animalia
Phylum
Mollusca
Class
Cephalopoda
Order
Octopoda
Family
Octopodidae
Scientific Name
Octopus Vulgaris

Fun Fact: There are around 300 different species!

The octopus holds the distinction of being the most intelligent of all invertebrate animals. With the highest brain-to-body-mass ratios of all invertebrates – higher even than those of some vertebrates – the octopus is regarded as the smartest of all invertebrate animals. These cephalopods are intelligent enough to engage in deceitful activities, including pretending to […] Read More


Oenpelli python

Oenpelli python Picture
Kingdom
Animalia
Phylum
Chordata
Class
Reptilia
Order
Squamata
Family
Pythonidae
Genus
Nyctophilopython
Scientific Name
Nyctophilopython oenpelliensis

Fun Fact: Oenpelli pythons are unusually thin for a python.

The Oenpelli python is a long, thin snake that reaches 16 feet and can change color. This species lives in a tiny region in Northern Territory, Australia. It is one of the rarest python species in the world. Amazing Facts About Oenpelli Pythons Where to Find Them This species only lives in Northern Territory, Australia. […] Read More


Oilfish

Oilfish Picture
Kingdom
Animalia
Phylum
Chordata
Class
Actinopterygii
Order
Scombriformes
Family
Gempylidae
Genus
Ruvettus
Scientific Name
Ruvettus pretiosus

Fun Fact: They live in deep water as far as 2,600 feet below the water’s surface.

“The oilfish is an opportunistic carnivore, eating what is abundant and easy to catch in its environment.” Summary The oilfish (Ruvettus pretiosus) is a species of snake mackerel found in the temperate and tropical waters in the Atlantic and Pacific Oceans. They inhabit deep waters, living in pairs and silently swimming through the dark water. […] Read More


Okapi

Okapi Picture
Kingdom
Animalia
Phylum
Chordata
Class
Mammalia
Order
Artiodactyla
Family
Giraffidae
Genus
Okapia
Scientific Name
Okapia johnstoni

Fun Fact: Eats more than 100 different types of plants!

Due to its long prehensile tongue, the okapi is one of the few animals in the world said to be able to lick its own ear! The okapi is an elusive herbivore present in only central Africa in a small area of tropical mountain forest. It has a long neck, in common with its close […] Read More


Old English Sheepdog

Old English Sheepdog Picture
Kingdom
Animalia
Phylum
Chordata
Class
Mammalia
Order
Carnivora
Family
Canidae
Genus
Canis
Scientific Name
Canis Lupus

Fun Fact: Intelligent, sociable and playful!

With its big shaggy coat, obscured eyes, and white and gray color scheme, the Old English Sheepdog is one of the most recognizable breeds in the world. Its very appearance seems to radiate friendly and approachable energy. History and Origin This breed originated at some point in the 19th century from the region of Cornwall […] Read More


Old House Borer

Old House Borer Picture
Kingdom
Animalia
Phylum
Arthropoda
Class
Insecta
Order
Coleoptera
Family
Cerambycidae
Genus
Hylotrupes
Scientific Name
Hylotrupes bajulus

Fun Fact: Depending on the habitat and climate, these beetles can live between 2 to 10 years, often staying in their larval stage for several years, making them extremely dangerous to wooden structures.

These beetles are known as pests because of their harmful ability to destroy wood. Older house borers are second only to termites in terms of the damage they cause. However, despite its name, the old house borer prefers newer wood. This is because fresher wood has a higher resin content. These beetles were first identified […] Read More


Oleander Hawk Moth

Oleander Hawk Moth Picture
Kingdom
Animalia
Phylum
Arthropoda
Class
Insecta
Order
Lepidoptera
Family
Sphingidae
Genus
Daphnis
Scientific Name
Daphnis nerii

Fun Fact: Oleander hawk moth caterpillars feed on the foliage of oleander, an extremely toxic plant to which they are immune.

The oleander hawk moth (Daphnis nerii) belongs to the hawk moth family. They’re most active at twilight. Due to their stunning appearance, Daphnis nerii is sought by naturalists, lepidopterists, and photographers. The larva of the oleander hawk moth is sometimes a pest, as it feeds on some plants such as the oleander plant (hence the […] Read More


Olingo

Olingo Picture
Kingdom
Animalia
Phylum
Chordata
Class
Mammalia
Order
Carnivora
Family
Procyonidae
Genus
Bassaricyon
Scientific Name
Bassaricyon gabbii

Fun Fact: Olingos are part of the raccoon family.

“Olingos are part of the raccoon family.“ Olingo Facts They possess anal scent glands which produce a pungent odor when the animal is scared. This is designed to drive enemies away. They are nocturnal animals. They are active in the night and sleep in tree cavities during the day. Although they are omnivores, they mostly eat fruit, […] Read More


Olive Baboon

Olive Baboon Picture
Kingdom
Animalia
Phylum
Chordata
Class
Mammalia
Order
Primates
Family
Cercopithecidae
Genus
Papio
Scientific Name
Papio anubis

Fun Fact: Olive baboons will sometimes form strong friendships with each other

“The olive baboon forms one of the most complex social structures in the animal kingdom.” This baboon is a type of old-world monkey (a monkey species from the Eastern Hemisphere) that roams across various habitats of Africa. They have numerous adaptations to help them survive and thrive in different environmental conditions. In this article, you […] Read More


Olive python

Olive python Picture
Kingdom
Animalia
Phylum
Chordata
Class
Reptilia
Order
Squamata
Family
Pythonidae
Genus
Liasis
Scientific Name
Liasis olivaceus

Fun Fact: The olive python is a gentle giant that is rarely aggressive.

The olive python is Australia’s third longest snake; only the Oenpelli python and amethystine python are longer. This very long but relatively docile snake is sometimes killed because people confuse it with the venomous king brown snake (Pseudechis australis). It is long and strong, and the adults often reach 13 feet long. The Pilbara olive […] Read More


Olive Sea Snake

Olive Sea Snake Picture
Kingdom
Animalia
Phylum
Chordata
Class
Reptilia
Order
Squamata
Family
Elapidae
Genus
Aipysurus
Scientific Name
Aipysurus laevis

Fun Fact: Olive sea snakes can stay underwater for two hours without taking a breath.

“Olive sea snakes can stay underwater for two hours without taking a breath” The olive sea snake is sometimes called the golden sea snake or the olive-brown sea snake because of its coloration. It can grow up to six feet long and weigh up to six and a half pounds. It has a venomous bite […] Read More


Olm

Olm Picture
Kingdom
Animalia
Phylum
Chordata
Class
Amphibia
Order
Caudata
Family
Proteidae
Genus
Proteus
Scientific Name
Proteus anguinus

Fun Fact: Inhabits dark underwater caves

The olm is the longest-living amphibian and can live to be 100 years old! One of the most fascinating creatures in a world full of fascinating creatures, the olm, like its distant relative the axolotl, is a completely aquatic salamander with gills and tailfins. It is born, lives its long lifespan, and eventually dies in […] Read More


Olympic Marmot

Olympic Marmot Picture
Kingdom
Animalia
Phylum
Chordata
Class
Mammalia
Order
Rodentia
Family
Sciuridae
Genus
Marmota
Scientific Name
Marmota olympus

Fun Fact: The Olympic marmot is found in only one location in the United States — the Olympic Mountains in Washington

The Olympic marmot is an endemic species found only in the Olympic Mountains of Washington. The species is the second-rarest North American marmot. This furry rodent hibernates without eating or drinking for seven to eight consecutive months from fall to late spring, relying on accumulated body fat and a much-reduced metabolism.  5 Olympic Marmot Facts […] Read More


Onagadori Chicken

Onagadori Chicken Picture
Kingdom
Animalia
Phylum
Chordata
Class
Aves
Order
Galliformes
Family
Phasianidae
Genus
Gallus
Scientific Name
Gallus gallus

Fun Fact: The Onagadori, the chicken with the world's longest tail, was declared a Natural Monument of Japan in 1952.

The Onagadori chicken of Japan has the longest tail in the world, with feathers growing up to 27 feet in length! The ornamental Onagadori chicken originated centuries ago in the Kochi Prefecture in Japan. These extremely long-tailed chickens were bred to preserve a mutation that prevented tail feathers from molting. This mutation allowed the birds […] Read More


Onager

Onager Picture
Kingdom
Animalia
Phylum
Chordata
Class
Mammalia
Order
Perissodactyla
Family
Equidae
Genus
Equus
Scientific Name
Equus hemionus

Fun Fact: An onager's coat changes color with the season.

An onager’s coat changes color with the season. Facts Endangered: Onagers are an endangered species of equines. Only 28,ooo exist in the world today.Almost extinct: Only 600-700 Persian onagers are left in the wild today.Good memory: Onagers are very intelligent animals. They have a great memory and can recall the face of someone they met […] Read More


Opabinia

Opabinia Picture
Kingdom
Animalia
Phylum
Arthropoda
Family
Opabiniidae
Genus
Opabinia
Scientific Name
Opabinia regalis

Fun Fact: Opabinia had five stalked eyes on its head.

One of the things studying earth’s ancient fossils has revealed is that the planet had some pretty odd creatures millions of years ago. Opabinia is one of such strange-looking creatures that swam the earth’s oceans 500 million years ago. Unearthed from Canada’s Burgess Shale, this ancient arthropod had an odd appearance; it looked like something […] Read More


Opah

Opah Picture
Kingdom
Animalia
Phylum
Chordata
Class
Actinopterygii
Order
Lampriformes
Family
Lampridae
Genus
Lampris
Scientific Name
Lampris guttatus

Fun Fact: Opah are brightly colored, with red-orange fins and a silvery body.

The opah is a large, colorful fish that makes a prize catch and a tasty meal. Opah are a family of large, circular fish that live mostly in tropical waters. They are brightly colored with red-orange fins and silvery bodies. They can grow up to 6 feet, making them a great catch for fishermen who […] Read More


Opaleye (Rudderfish)

Opaleye (Rudderfish) Picture
Kingdom
Animalia
Phylum
Chordata
Class
Actinopterygii
Order
Perciformes
Family
Kyphosidae
Genus
Girella Gray
Scientific Name
Girella nigricans

Fun Fact: Some indigenous people of the Pacific coast of North America consider opaleye fish sacred food and use it in traditional ceremonies.

Opaleye is a species of fish indigenous to the Pacific coast of North America. It is a member of the Pleuronectidae family, which includes other flatfish such as soles and flounders. They live in rocky tide pools and intertidal areas where they can reach lengths of up to 25 inches and weigh 13 pounds fully […] Read More


Opossum

Opossum Picture
Kingdom
Animalia
Phylum
Chordata
Class
Mammalia
Order
Didelphimorphia
Family
Didelphidae
Genus
Didelphis
Scientific Name
Didelphis Virginiana

Fun Fact: Thought to be immune to certain snake venom!

Opossums hold the distinction of being the only marsupial that lives in the United States and Canada! Throughout much of United States history, opossums were animals that were widely hunted and consumed by people. Although this remains true in some areas of the southern U.S., these savvy marsupials are now better known as pests due […] Read More


Oranda Goldfish

Oranda Goldfish Picture
Kingdom
Animalia
Phylum
Chordata
Class
Actinopterygii
Order
Cypriniformes
Family
Cyprinidae
Genus
Carrassius
Scientific Name
Carassius auratus auratus

Fun Fact: Oranda goldfish are one of the most popular fancy goldfish breeds

Summary The Oranda goldfish is a fascinating breed of goldfish from the Carp family that was developed in the aquarium trade industry and originated from China and Japan. The Oranda is a type of ornamental goldfish that is known for its wen- which resembles a large jelly-like growth on their heads. This type of goldfish […] Read More


Orange Baboon Tarantula

Orange Baboon Tarantula Picture
Kingdom
Animalia
Phylum
Arthropoda
Class
Arachnida
Order
Araneae
Family
Theraphosidae
Genus
Pterinochilus
Scientific Name
Pterinochilus murinus

Fun Fact: Their nickname is "Orange Bitey Thing"!

The orange baboon tarantula is both orange and ornery. The orange baboon tarantula (OBT) is covered in bright orange bristles. Their faces resemble furry, orange baboons. OBT’s, as they are sometimes referred to, are known to have an ornery disposition and can act aggressively. They can grow to be similar in size to the Mexican […] Read More


Orange Dream Ball Python

Orange Dream Ball Python Picture
Kingdom
Animalia
Phylum
Chordata
Class
Reptilia
Order
Squamata
Family
Pythonidae
Genus
Python
Scientific Name
Python regius

Fun Fact: The "Orange Dream" name came from the idea that the morph would make its first breeder a million dollars.

The orange dream ball python is a popular color morph that started as a mutation. These snakes have bright orange instead of brown markings with a white belly. One of the hundreds of color mutations in ball pythons, orange dream combines with others to create bright and beautiful color patterns. 3 Facts About The Orange […] Read More


Orange Roughy 

Orange Roughy  Picture
Kingdom
Animalia
Phylum
Chordata
Class
Actinopterygii
Order
Trachichthyiformes
Family
Trachichthyidae
Genus
Hoplostethus
Scientific Name
Hoplostethus atlanticus

Fun Fact: One of the oldest commercially harvested fish

Summary Able to live over 200 years, the orange roughy is a deep-sea fish belonging to the slimehead family Trachichthyidae. They mature extremely slowly, which makes them highly susceptible to overfishing. They possess rounded heads covered in mucous-filled canals, hence their name.  When active or feeding, they tend to appear orangish-red, but they slowly lose […] Read More


Orange Spider

Orange Spider Picture
Kingdom
Animalia
Phylum
Arthropoda
Class
Arachnida
Order
Araneae
Family
Araneidae
Genus
Araneus
Scientific Name
Araneus marmoreus

Fun Fact: Orange spiders make vertically-oriented webs for catching prey.

“Orange spiders make vertically oriented webs for catching prey.” The marbled orb weaver, popularly known as the orange spider, looks like a pumpkin with legs, thanks to a distinct orange color and inflated abdomen. It is one of the most common garden spiders in North America. The species makes vertically oriented webs on trees, shrubs, […] Read More


Orange Tanager (Orange-Headed Tanager)

Orange Tanager (Orange-Headed Tanager) Picture
Kingdom
Animalia
Phylum
Chordata
Class
Aves
Order
Passeriformes
Family
Thraupidae
Genus
Thylpopsis
Scientific Name
Thlypopsis sordida

Fun Fact: They inhabit the lowlands of the Amazon rainforest

“It lives in the lowlands of the Amazon rainforest.” Summary The orange tanager (orange-headed tanager) is a small bird native to the neotropical region of South America. It spends its days foraging in trees and shrubs for insects, often with a small group. Though relatively uncommon, they have an extensive range and learn to adapt […] Read More


Orange-Crowned Warbler

Orange-Crowned Warbler Picture
Kingdom
Animalia
Phylum
Chordata
Class
Aves
Order
Passeriformes
Family
Parulidae
Genus
Leiothlypis
Scientific Name
Leiothlypis celata

Fun Fact: Often mistaken for the Tennessee Warblers, which are equally dull.

The orange-crowned warbler is a unique songbird who primarily lives in the western hemisphere. This bird has a high-pitched trill for a song, and males even have different songs to differentiate them from each other. Both parents take care of the young, though only the mother incubates the eggs for just under 2 weeks. Orange-Crowned […] Read More


Orangutan

Orangutan Picture
Kingdom
Animalia
Phylum
Chordata
Class
Mammalia
Order
Primates
Family
Hominidae
Genus
Pongo
Scientific Name
Pongo pygmaeus, Pongo abelii, Pongo tapanuliensis

Fun Fact: Shares 97% of its DNA with humans!

Classification The orangutan is one of the largest primates in the world and is the only member of the great ape family that is found outside of Africa. There are three species of orangutan found in the steamy jungles on the islands of Borneo and Sumatra, which are the Bornean orangutan, the Sumatran orangutan, and […] Read More


Orb Weaver

Orb Weaver Picture
Kingdom
Animalia
Phylum
Arthropoda
Class
Arachnida
Order
Araneae
Family
Araneidae

Fun Fact: Females are about four times the size of males

The Orb Weaver is a spider commonly found outside homes, in hedges, tall grasses, and trees. They are a helpful predator who feeds off the pest bugs we don’t like, such as mosquitoes, beetles and other bothersome flying insects. They build elaborate, circular webs and are most often seen in late summer and early fall. […] Read More


Orchard Oriole

Orchard Oriole Picture
Kingdom
Animalia
Phylum
Chordata
Class
Aves
Order
Passeriformes
Family
Icteridae
Genus
Icterus
Scientific Name
Icterus spurius

Fun Fact: They use rapid wingbeats to hover over foliage as they search for food.

“They are easy-going birds who show little aggression toward other bird species.” Summary The orchard oriole (Icterus spurius) is a small passerine bird native to North and South America, inhabiting orchards and woodland edges. These social birds are easy-going and show little aggression, often joining mixed-species groups. Listen for the male’s rapid musical songs during […] Read More


Orchid Dottyback

Orchid Dottyback Picture
Kingdom
Animalia
Phylum
Chordata
Class
Actinopterygii
Order
Perciformes
Family
Pseudochromidae
Genus
Pseudochromis
Scientific Name
Pseudochromis fridmani

Fun Fact: This fish camouflages as its prey's parents to trick it into becoming dinner.

This fish camouflages as its prey’s parents to trick it into becoming dinner. Facts The orchid dottyback is a brilliantly purple fish. They are sought after by aquarium owners to spruce up their tank’s appearance.The orchid dottybacks; generic name, Pseudochromis, means false color, because the fish has the ability to mimic the colors of its […] Read More


Oregon Spotted Frog

Oregon Spotted Frog Picture
Kingdom
Animalia
Phylum
Chordata
Class
Amphibia
Order
Anura
Family
Ranidae
Genus
Rana
Scientific Name
Rana pretiosa

Fun Fact: Oregon spotted frogs are the most endangered frogs in Canada!

The Oregon spotted frog is an endangered species of frog native to the Pacific Northwest. It has a range spanning Canada and the United States, although most of the frogs no longer inhabit these regions due to their rarity. They have characteristic black spots with light centers and spend most of their time in the […] Read More


Ori-Pei

Ori-Pei Picture
Kingdom
Animalia
Phylum
Chordata
Class
Mammalia
Order
Carnivora
Family
Canidae
Genus
Canis
Scientific Name
Canis familiaris

Fun Fact: Ori-Pei's are born with short noses, which causes them to grunt and make a lot of noise when they breathe.

The ori-pei is a hybrid mix breed of purebred parents, namely the Chinese shar-pei and pug. The ori-pei originated in North America in the year 1970. A Chinese shar-pei breeder, Aaron Silver, grew very fond of the shar-pei breed but disapproved of their health issues. At that time, he decided to create a hybrid breed […] Read More


Oribi

Oribi Picture
Kingdom
Animalia
Phylum
Chordata
Class
Mammalia
Order
Artiodactyla
Family
Bovidae
Genus
Ourebia
Scientific Name
Ourebia ourebi

Fun Fact: Males oribis spend most of their time patrolling the borders of their territories; they can do this about 16 times an hour! However, 27% of their day is spent grazing.

Summary Oribis are unique little antelope because they can adapt well to most environments, which is why they can be found scattered across the African continent. While there are a few solitary males, they generally live in breeding pairs or groups of three, consisting of one male and two females. Female oribis sexually mature at […] Read More


Oriental Cockroach

Oriental Cockroach Picture
Kingdom
Animalia
Phylum
Arthropoda
Class
Insecta
Order
Blattodea
Family
Blattidea
Genus
Blatta
Scientific Name
Blatta orientalis

Fun Fact: Unlike other cockroach species that live indoors living off humans, oriental cockroaches are outdoor scavengers. 

Unlike other cockroach species that live indoors living off humans, oriental cockroaches are outdoor scavengers.  Summary The Oriental cockroach is a large, shiny cockroach with a dark brown or almost black color. Like other cockroach species, oriental cockroaches are scavengers. However, they live in outdoor habitats rather than indoors. Oriental cockroaches are also called water […] Read More


Oriental Dwarf Kingfisher

Oriental Dwarf Kingfisher Picture
Kingdom
Animalia
Phylum
Chordata
Class
Aves
Order
Coraciiformes
Family
Alcedinidae
Genus
Ceyx
Scientific Name
Ceyx erithaca

Fun Fact: They are one of the smallest kingfishers!

“They like to live near forest streams and ponds with plenty of canopy shade.” Summary The oriental dwarf kingfisher (Ceyx erithaca), also known as the black-backed kingfisher, is a tiny bird only slightly bigger than a hummingbird. They live in southeast Asia, where they inhabit evergreen and deciduous forests near streams and ponds. They stay […] Read More


Orinoco Crocodile

Orinoco Crocodile Picture
Kingdom
Animalia
Phylum
Chordata
Class
Reptilia
Order
Crocodylia
Family
Crocodylidae
Genus
Crocodylus
Scientific Name
Crocodylus intermedius

Fun Fact: Orinoco crocodiles are the largest predators in South America; they're also going extinct!

“Orinoco crocodiles are the largest predators in South America; they’re also going extinct!” Facts Orinoco crocodiles are the largest predators in South America. They are also apex predators which means they sit comfortably at the top of the food chain.A living fossil: You can trace the Orinoco crocodile back 240 million years ago! They also […] Read More


Ornate Bichir

Ornate Bichir Picture
Kingdom
Animalia
Phylum
Chordata
Class
Actinopterygii
Order
Polypteriformes
Family
Polypteridae
Genus
Polypterus
Scientific Name
Polypterus ornatipinnis

Fun Fact: The ornate bichir can survive outside water for short periods of time

The ornate bichir can survive outside water for long periods of time.  Summary Polypterus ornatipinnis, also called ornate bichir, is a species of freshwater fish native to Central and Eastern Africa. More specifically, the fish is found in Lake Tanganyika and the Congo River Basin. This fish is the largest of the “upper jaw bichirs” […] Read More


Ornate Black-Tailed Rattlesnake

Ornate Black-Tailed Rattlesnake Picture
Kingdom
Animalia
Phylum
Chordata
Class
Reptilia
Order
Squamata
Family
Viperidae
Genus
Crotalus
Scientific Name
ornatus

Fun Fact: Ornate black-tailed rattlesnake mothers stay with their newborn babies for up to a month.

Ornate black-tailed rattlesnakes are among the most beautiful snakes in the Americas. These mild-mannered snakes usually slither away before giving away their position by rattling. But be careful not to step on them because they can deliver a painful venomous bite.  Their lack of legs allow them to slither in and out of places off […] Read More


Ornate Box Turtle

Ornate Box Turtle Picture
Kingdom
Animalia
Phylum
Chordata
Class
Reptilia
Order
Testudines
Family
Emydidae
Genus
Terrapene
Scientific Name
Terrapene Ornata

Fun Fact: One of the biggest threats to the orate box turtle population is that when during extremely hot or cold breeding season a vast majority of the hatchlings are of one sex.

“Ornate box turtles can live up to 40 years in the wild!” Ornate Box Turtle Summary The ornate box turtle is one of two commonly found land turtles in the plains of the USA. The animal is the state reptile of Nebraska and Kansas and is commonly found in the grasslands in both states. Unlike […] Read More


Ornithocheirus

Ornithocheirus Picture
Kingdom
Animalia
Phylum
Chordata
Order
Pterosauria
Family
Ornithocheiridae
Genus
Ornithocheirus
Scientific Name
Ornithocheirus simus

Fun Fact: Scientists once considered the Ornithocheirus an ancestor to modern birds

The Ornithocheirus was a pterosaur (flying reptile) that lived during the Albian Stage of the Early Cretaceous Period, about 110 million years ago. Fossils of the Ornithocheirus have been found in the United Kingdom and Morocco. The Ornithocheirus was a flying predator. It was a piscivore, which means it hunted and primarily ate fish. It […] Read More


Ornithomimus

Ornithomimus Picture
Kingdom
Animalia
Phylum
Chordata
Family
†Ornithomimidae
Genus
†Ornithomimus

Fun Fact: Ornithomimus translates from Greek to mean “bird mimic.”

Description & Size of the Ornithomimus Ornithomimus is a genus of ornithomimid dinosaur, and its name translates from Greek to mean “bird mimic.” As you imagine what you think of a dinosaur, you’ll be surprised to find that the Ornithomimus looks nothing like it. Compared to other dinosaurs, the Ornithomimus was a medium-sized animal. When […] Read More


Ortolan Bunting

Ortolan Bunting Picture
Kingdom
Animalia
Phylum
Chordata
Class
Aves
Order
Passeriformes
Family
Emberizidae
Genus
Emberiza
Scientific Name
Emberiza hortulana

Fun Fact: The tradition of hiding your face with a napkin or towel while eating this bird was begun by a priest who was a friend of the great French gastronome Jean Anthelme Brillat-Savarin.

“The Ortolan Bunting is The Little Bird That is Forbidden Food” Of all the weird gastronomic traditions humans indulge in, eating this inoffensive little bird is one of the weirdest and frankly, one of the cruelest. Yet it is a rite of passage for the well-heeled, as can be seen in TV shows such as […] Read More


Oscar Fish

Oscar Fish Picture
Kingdom
Animalia
Phylum
Chordata
Class
Actinopterygii
Order
Perciformes
Family
Cichlidae
Genus
Astronotus
Scientific Name
Astronotus ocellatus

Fun Fact: The Oscar fish has teeth in its throat!

“An intelligent and companionable fish” People who own Oscar fish might have bought one or two for their beautiful colors, but soon they’re surprised to see that the fish has a personality. They’ll notice their pet Oscar seems to be watching them as they go about their business. They may even believe that their Oscar […] Read More


Osprey

Osprey Picture
Kingdom
Animalia
Phylum
Chordata
Class
Aves
Order
Accipitriformes
Family
Pandionidae
Genus
Pandion
Scientific Name
Pandion haliaetus

Fun Fact: They reuse nesting sites for 70 years!

“Their wings make an “M” shape when seen from below.” Summary The osprey (Pandion haliaetus) is a large raptor inhabiting every continent except Antarctica. They live near bodies of water abundant with fish, such as coastal estuaries and salt marshes. Look for them soaring above the water and diving feet first to catch their prey […] Read More


Ostracod

Ostracod Picture
Kingdom
Animalia
Phylum
Arthropoda
Class
Ostracoda

Fun Fact: Oldest and most common extant crustaceans

The most common of ancient crustaceans, ostracods are tiny crustaceans in the class Ostracoda. Scientists have identified around 70,000 individual ostracods, but only 13,000 or so exist to this day. While most ostracods live in marine habitats, some also live in freshwater, and a few live on land. They range in size from 0.008 to […] Read More


Ostrich

Ostrich Picture
Kingdom
Animalia
Phylum
Chordata
Class
Aves
Order
Struthioniformes
Family
Struthionidae
Genus
Struthio
Scientific Name
Struthio camelus

Fun Fact: The largest bird in the world!

The ostrich is among the largest types of birds in the world. The ostrich bird looks like an unusual chimera cooked up in a lab. When writing about the ostrich, the Greek philosopher Aristotle did not know whether to classify it as a bird or a mammal. But in fact, the ostrich belongs to that […] Read More


Otter

Otter Picture
Kingdom
Animalia
Phylum
Chordata
Class
Mammalia
Order
Carnivora
Family
Mustelidae

Fun Fact: There are 13 different species worldwide

“Giant otters are notorious chatterboxes“ Just like many people, there are giant otters that are considered chatterboxes for their species. Though they can’t form words, they have a vocabulary that consists of 22 recognizable noises. Each noise is used to address a different type of situation. This is how giant otters effectively communicate with each […] Read More


Otterhound

Otterhound Picture
Kingdom
Animalia
Phylum
Chordata
Class
Mammalia
Order
Carnivora
Family
Canidae
Genus
Canis
Scientific Name
Canis lupus

Fun Fact: Otterhounds have webbed feet making them great swimmers!

Otterhounds have webbed feet and are expert swimmers! The history of this shaggy dog dates all the way back to 14th century England. These dogs were bred to hunt otters and remove them from streams and lakes. This is so otters couldn’t steal the fish away from fishermen in the area. Bloodhounds and French hounds […] Read More


Ovenbird

Ovenbird Picture
Kingdom
Animalia
Phylum
Chordata
Class
Aves
Order
Passeriformes
Family
Parulidae
Genus
Seiurus
Scientific Name
Seiurus aurocapilla

Fun Fact: The ovenbird is named for its unusual nest, which is shaped like an oven!

The ovenbird is named for its unusual nest, which is shaped like an oven! The ovenbird is kind of punk rock. It wears a jacket of olive feathers and has an orange mohawk-like stripe down the middle of its crown, lined on either side in black. When it gets agitated it can raise this stripe […] Read More


Oviraptor

Oviraptor Picture
Kingdom
Animalia

Fun Fact: Oviraptor means "egg thief" or "egg seizer," though they were quite protective of their own eggs.

The Oviraptor is a genus of oviraptorid dinosaur. The name is Latin for “egg thief,” which is what scientists originally believed it to be. However, additional research suggests that the parents of this species were quite protective, protecting a nest instead of attacking it as food. Oviraptors ruled in big numbers during the late Cretaceous […] Read More


Owl

Owl Picture
Kingdom
Animalia
Phylum
Chordata
Class
Aves
Order
Strigiformes

Fun Fact: The owl can rotate its head some 270 degrees

Owls are exceptional hunters that can spot potential prey from up to half a mile away. Owls are a diverse group of animals that belong to their own separate order. There are more than 200 recognized species all around the world. With their highly developed binocular vision and accurate flying abilities, they have several unique […] Read More


Owl Butterfly

Owl Butterfly Picture
Kingdom
Animalia
Phylum
Arthropoda
Class
Insecta
Order
Lepidoptera
Family
Nymphalidae
Genus
Caligo

Fun Fact: Owl butterflies derive their name from big spots on each hindwing that resemble owl eyes

The owl butterfly is a fascinating specimen native to the rainforests of Central America. They derive their name from big spots on each hindwing that resemble owl eyes. These spots are not decorative; they are a defense mechanism used to deter birds from eating them. This species belongs to the family Nymphalidae, consisting of large-sized […] Read More


Owlfly (Ascalaphidae)

Owlfly (Ascalaphidae) Picture
Kingdom
Animalia
Phylum
Arthropoda
Class
Insecta
Order
Neuroptera
Family
Ascalaphidae

Fun Fact: Adult owlflies can capture prey while flying in the air.

The name “owlfly” applies to any member of the large Ascalaphidae family of insects. They have long slender bodies with membranous wings. The appearance of the owlfly is similar to that of the dragonfly, and both insects are often mistaken for each other. The larvae of this insect are ambush predators typically found on trees […] Read More


Ox

Ox Picture
Kingdom
Animalia
Phylum
Chordata
Class
Mammalia
Order
Artiodactyla
Family
Bovidae
Genus
Bos
Scientific Name
Bos taurus

Fun Fact:

The ox is the heavy-duty machinery of the animal world. An ox, by definition, is any male bovine that is used for work. Usually, only mature males (over 4 years of age) from the largest breeds of domesticated cattle are trained for work, and these males are castrated to keep them docile. Certain cattle are […] Read More


Oxpecker

Oxpecker Picture
Kingdom
Animalia
Phylum
Chordata
Class
Aves
Order
Passeriformes
Family
Buphagidae
Genus
Buphagus
Scientific Name
Buphagus erythrorhyncus & Buphagus africanus

Fun Fact: The oxpecker, known as the rhino’s guard, alerts its host to danger with a loud commotion

The oxpecker, known as the rhino’s guard, alerts its host to danger with a loud commotion! The oxpecker is a native of sub-Saharan Africa that spends most of its life on the backs of its hosts. It feeds on ticks, larvae and other parasites that infest large mammals like the black rhinoceros, African buffalo, hippopotamus […] Read More


Oyster

Oyster Picture
Kingdom
Animalia
Phylum
Mollusca
Class
Bivalvia
Order
Ostreoida
Family
Ostreidae
Scientific Name
Ostreidae

Fun Fact: Can process up to 10 litres of water an hour!

Oysters make up a family of a large number of salt-water bivalve mollusks. Oysters are marine animals that are often found in brackish habitats. They are very irregular in shape and the valves of some are highly calcified. They belong to the phylum Mollusca. Oysters are animals that eat algae and other food particles that […] Read More


Oyster Toadfish

Oyster Toadfish Picture
Kingdom
Animalia
Phylum
Chordata
Class
Actinopterygii
Order
Batrachoidiformes
Family
Batrachoididae
Genus
Opsanus
Scientific Name
Opsanus tau

Fun Fact: The oyster toadfish can produce poison to protect itself

“The oyster toadfish is also known as the ugly toad.” The oyster toadfish is a strange-looking (some may even say ugly) fish that makes its home in the secluded holes and hiding spots along the shore of the eastern United States. The bumpy skin, long mouth, and bulging eyes have earned it very appropriate comparisons […] Read More


Ozark Bass

Ozark Bass Picture
Kingdom
Animalia
Phylum
Chordata
Class
Actinopterygii
Order
Perciformes
Family
Centrarchidae
Genus
Ambloplites
Scientific Name
Ambloplites constellatus

Fun Fact: Ozark Bass only live in Arkansas and Missouri

“Ozark bass only inhabit the tributaries of White River, and very little is known about them.” Summary Native to White River tributaries in Arkansas and Missouri, Ozark bass populations do not reach far. The fish species is unique in that they cannot be found anywhere else in the United States. Their concentrated population has not […] Read More



A Ocelot
Ocelot

Also known as the Painted Leopard!

A Old English Sheepdog
Old English Sheepdog

Intelligent, sociable and playful!

Newest Animals that Start with the Letter O

The most recently added Animals that start with the letter O.

A Ornate Black-Tailed Rattlesnake
Ornate Black-Tailed Rattlesnake

Ornate black-tailed rattlesnake mothers stay with their newborn babies for up to a month.

A Ocean Perch
Ocean Perch

As a scorpionfish, the ocean perch has spines along its back!

A Ocean Pout
Ocean Pout

Females guard their eggs for up to 3 months

Animals that start with the letter O, including the Ocelot & Old English Sheepdog
Share on:
About the Author

AZ Animals is a growing team of animals experts, researchers, farmers, conservationists, writers, editors, and -- of course -- pet owners who have come together to help you better understand the animal kingdom and how we interact.

Thank you for reading! Have some feedback for us? Contact the AZ Animals editorial team.