Home Animals Animals That Start With O: 20 Outstanding Animals

Animals That Start With O: 20 Outstanding Animals


The animal kingdom is full of fascinating creatures, and those that start with O are no exception. From the enormous and powerful orca to the tiny and adorable opossum, there is a wide range of animals to discover. The oceanic ocean sunfish is a particularly intriguing creature, with its unique circular shape and impressive size. 

And let’s not forget about the odd-looking yet incredibly intelligent octopus, known for its ability to change color and shape. Whether you’re a fan of land-dwelling or aquatic animals, this collection of some of the most interesting animals that start with O is sure to delight and surprise you. Prepare to have your mind blown by these captivating creatures.

Overview of Animals That Start With O

1. Ox

Animals That Start With O

Oxen are fascinating creatures that can be found worldwide. Originally discovered in Asia, Central, and South America, they have since spread across the globe. These herbivores travel in groups and are known to form herds in the wild. Though they can be preyed upon by bears and wolves, they have managed to survive and thrive with their hardy and resilient nature. Interestingly, oxen, also known by the name of bollocks, are unique as they are the only species in their Genus, Bos. For more than 2500 years, they have assisted humans in various ways.  

2. Owl

Stealthy Animals

Owls are some of the most fascinating creatures in the animal kingdom. One of their most distinctive features is their flat faces, bulging eyes, and protruded beaks, which give them a unique and intimidating appearance. Owls have excellent eyesight and are far-sighted, making them adept at spotting prey from a distance. It’s no surprise that they are notorious for preying on various animals, particularly small-sized mammals, birds, and insects. Although many species of owls are creatures of the night, some are active during the day. Perhaps the most intriguing aspect of these birds is their ability to rotate their necks to about 270 degrees, allowing them to look behind themselves without even turning their bodies.  

3. Oyster

The shape of these fascinating marine creatures is quite unique – having an irregular shape that sets them apart from other sea creatures. Their shells are oval in shape and can vary in color from grey to white. Oysters are not only visually intriguing but have a vital role in the ecosystem as a source of protein and nutrients for many animals. However, they are also prey for a variety of predators, including seabirds, crabs, and even humans. Oysters may seem vulnerable, but don’t let that fool you, as they have developed a survival strategy by having eyes all over their bodies to detect potential danger.  

4. Oscar fish

Are you looking for a unique and interesting pet? Look no further than the Oscar fish. With a life span of 20 years, these fish make great long-term companions. They are also prolific breeders, able to lay up to 250-3000 eggs at once, and their offspring has a different color from the parents. Oscar fish are omnivores and enjoy eating algae, fruits, and even small insects and fish. But beyond their dietary habits, they are also intelligent and monogamous, making them not just fascinating to watch, but also loving pets. And here’s a fun fact: Oscar fish have teeth in their throat!  

5. Orca

The orca, also known as the killer whale, is truly a citizen of the world. This fascinating species is considered cosmopolitan and can be found in virtually every ocean on the planet. One of the things that sets them apart from other whales is their teeth. Unlike filter-feeders who strain tiny organisms from the water, orcas have razor-sharp teeth that help them tear apart their prey. Being apex predators, they have an incredibly diverse diet, including everything from small fish to humans. And here’s a fun fact – they even prey on blue whales, the largest animals on the planet! 

6. Old English sheepdog

If you’re on the hunt for a furry and friendly companion, Old English dogs may just be the breed for you. With long, thick coats and adorable concealed eyes, these pets are sure to turn heads wherever they go. But don’t let their cute appearance fool you – these dogs are also impressively intelligent and playful. Whether you’re looking for a hiking buddy or a cozy lapdog, an Old English is sure to fit the bill. And if you’re a history buff, you’ll appreciate that these pups were discovered back in the 19th century in southeast England, giving them their unique name.  

7. Ostrich

When you think of big land animals, elephants and giraffes might come to mind, but don’t forget about the ostrich! These birds are massive and can stand up to 9 feet tall. They may not be able to fly, but that doesn’t mean their wings go to waste. Male ostriches use their wings to balance themselves while running and also to impress potential mates during courtship displays. Have you ever seen a male ostrich fluff up his feathers and twirl around to impress a female? It’s quite a sight to see! Ostriches are also known for their two-toed feet, which set them apart from other bird species.  

8. Otter

otters eating fish

Otters are fascinating creatures that have caught the attention of many people. Known to man are 13 species of otters, with eleven of them being river otters and the other two being sea and marine otters. Their thick fur allows them to stay afloat on the water’s surface and also provides insulation against cold temperatures. What makes these creatures even more interesting is that they are very playful animals that live in family groups. Otters are noisemakers and use 22 recognizable vocabularies to communicate with one another.  

9. Oilbird

The Northern areas of South America are home to some fascinating nocturnal birds. These creatures have adapted extremely well to their environment and primarily feed on oil palm fruits and tropical laurels. What’s truly unique about these birds is where they live – in caves! To navigate through the darkness, they’ve developed excellent eyesight and the ability to echolocate. But did you know that these birds were once boiled down to produce oil in ancient times?  

10. Orangutan


Orang-utans, also known as the Red Apes, are one of the largest primates worldwide. These intriguing creatures spend most of their time up in the trees, munching on insects, fruits, and barks. Interestingly, they are omnivores, which means they feast on both plants and animals. These endangered species can only be found in Asia, making them even more unique and special. But the most fascinating fact about the Orang-utans is that they share an incredible 97% of their DNA with humans!  

11. Osprey

osprey feeding

The osprey is a stunning bird with an unmistakable appearance. Their sleek head is adorned with a striking white color and an encircling black mask around their eyes. Though their habitat spans a variety of temperatures and regions, these birds are most commonly found in tropical and temperate areas. In fact, the osprey is often referred to as the Fishhawk due to their insatiable appetite for fish. It’s impressive to note that these creatures have wings that can take them soaring through the skies, boasting an impressive wingspan of about five feet!  

12. Opossum


Have you ever heard of an animal that can withstand snake bites without any harm? Meet the opossum, a remarkable creature known for its immunity to venom. These fruit-loving animals are found in areas close to rivers, like forests and farmland. They have four limbs and a tail, perfect for balancing and climbing trees. However, their most fascinating feature is the pouch they carry around, which acts as a secure home for their babies until they mature.  

13. Orb Weaver

Orb weavers are an intriguing species with their skull-like heads and diverse prey. These arachnids, also known as grass weavers, have a lifespan of six months to potentially make themselves known to curious observers. These spiders have a unique appearance that might make some people uneasy, but it’s their prey that truly brings out their power. Orb weavers are efficient hunters with a taste for multiple insects, including mosquitoes, gnats, flies, grasshoppers, and moths.  

14. Octopus

The Deadly Blue Ringed Octopus

These intelligent invertebrates, with about 300 species worldwide, are known for their solitary lifestyle and soft, slippery bodies. But don’t let their soft exterior fool you. Octopuses are escape artists, using their pliable bodies to slip out of predicaments at lightning speed. With this incredible flexibility, it’s no surprise that they can even fit through a hole the size of a quarter! These fascinating creatures live in the waters of temperate and tropical regions, making their homes in the ocean’s depths.  

15. Ornate Hawk-Eagle

Then you think of Brazil, you might picture beautiful beaches or lush rainforests. However, one of the most striking features of this country is the ornate hawk-eagle. These birds are truly a sight to behold, with their large crests and regal presence. You might catch a glimpse of them perched high up in a tree, scanning the branches for their next meal. What’s surprising about these majestic creatures is that they’re not afraid to take on prey much larger than themselves.  

16. Olm

Imagine spending your entire life in complete darkness, only coming out to feed in the cool, crisp waters of nearby rivers and lakes. This is the reality for European olms, fascinating creatures that live their entire life cycle within the confines of caves. These remarkable vertebrates, sporting a characteristic white or pink hue, are perfectly adapted to their environment, feeding exclusively on insects that thrive in water bodies. Interestingly, when exposed to light, they undergo an incredible transformation, turning jet black in color.  

17. Olive baboon

The olive baboon is a fascinating primate, predominantly found in the wilds of Africa. Their greyish-brown fur is a distinguishing characteristic, and their height is impressive as an adult can grow to up to 3 feet. What’s unique about them is their omnivorous palate, ranging from fruits to young antelopes. But it’s their strong social bonds that truly set them apart. Watching a troop of olive baboons interact and care for each other is a sight to behold. And while this primate has numerous quirks, perhaps the most shocking is that they only sexually mature around 35 years old.  

18. Okapi

Nature is full of unique creatures, and one herbivore that stands out is found in Africa. It’s characterized by white and black stripes on its limbs, making it easy to spot among other animals. Although it feeds on the usual diet of fruit, leaves, and stems, it also has a rather curious habit when the food supply is low: eating reddish clay. Yes, you read that right. These creatures turn to clay when their hunger pangs hit hard. It’s fascinating to see how their survival instincts come into play during lean times. 

19. Ocelot

Painted leopards might sound like a mythical creature straight out of a fairytale, but they actually refer to a real animal – ocelots. These carnivores are found in central and southern America and are known to prey on rodents and deer. However, their soft and velvety fur almost caused them to become extinct in the 20th century. Despite their beauty, it is important to remember that these creatures are predators and play a vital role in maintaining the balance of their ecosystem.

20. Oryx

Oryxes are fascinating animals that often confuse people who see them for the first time. While they have similar physical characteristics to antelopes, such as their sleek body and impressive speed, what sets them apart are their straight horns and intricate markings on their limbs and faces. These features make them stand out in a crowd but also help them to blend into their desert surroundings. Ironically, their biggest predators are not from the desert but are wolves and humans.  


What animals begin with O?

Animals that begin with the letter “O” include the octopus, which is a fascinating marine creature known for its unique appearance and intelligence. It has eight arms, and a soft body, and can change color and texture to camouflage itself in its surroundings. Another animal is the orangutan, a large, tree-dwelling primate native to the rainforests of Southeast Asia. These intelligent apes are known for their distinctive reddish-brown fur and their close genetic relation to humans.

What zoo animals start with an O?

Orangutans are often popular attractions in zoos due to their close resemblance to humans and their engaging behavior. Additionally, some zoos may have the opportunity to showcase otters, another animal that begins with an “O.” Otters are playful and social creatures that are a delight to watch as they frolic in their watery habitats.

What land animals start with O?

The oryx is a majestic antelope known for its striking long, straight horns and elegant appearance. These desert-dwelling creatures have adapted to harsh environments and are known for their impressive speed and endurance. On the other hand, the ocelot is a small wild cat with a beautiful coat adorned with distinctive spots and stripes. Native to the Americas, ocelots are skilled hunters and mostly nocturnal, making them elusive and captivating to observe in their natural habitats.

Final Words

In conclusion, animals that start with the letter O may not be as well-known as their counterparts in other letters, but they are certainly fascinating creatures. From the massive and mighty orca to the mysterious and elusive okapi, these animals each have unique qualities and characteristics that make them worthy of recognition and respect. Whether you are a nature lover or simply curious about the animal kingdom, exploring the world of animals that start with O can introduce you to a whole new world of wonder and awe. So take a closer look and discover the beauty and diversity of these amazing creatures.


Author Profile
Jeevan Kodiyan
Zoologist | Wildlife Conservation at Animals Research

An animal enthusiast with an interest in zoology, studying the behavior and activities of animals in the wild habitat. I work on research projects related to species conservation and endangered species protection. I also leverage zoology to become an educator, educating others about the importance of protecting our natural environment and the beauty of animals in their natural habitats.

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An animal enthusiast with an interest in zoology, studying the behavior and activities of animals in the wild habitat. I work on research projects related to species conservation and endangered species protection. I also leverage zoology to become an educator, educating others about the importance of protecting our natural environment and the beauty of animals in their natural habitats.


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