When most of us think of whales and dolphins, we imagine elegant blue whales, striking orcas, or the beautifully streamlined bottlenose dolphin. But the whale and dolphin family (collectively called cetaceans) contains over 90 living species; many of them unusual and little-known, and some stranger than fiction.
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From spiral tusks to big square heads, these oddities reveal how evolution thrives in the ocean’s depths. Here are ten of the more wonderfully weird whales and dolphins alive today.
Weirdest dolphins and whales in the world
Narwhal
No list of unusual whales is complete without the narwhal, nicknamed the 'unicorn of the sea.' This Arctic-dweller sports a single spiral tusk – actually an elongated upper-left tooth – that can grow nearly three meters long. Scientists now know that it’s packed with sensory nerves, allowing narwhals to detect changes in water temperature, salinity and pressure. Despite its mythical appearance, the tusk is not used for jousting but for subtle communication, sensing the environment and even play.
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Amazon river dolphin
Unlike sleek grey oceanic dolphins, the endangered Amazon river dolphin – or boto – is large, robust and strikingly pink. Their oddly flexible necks (unlike ocean dolphins, they have unfused vertebrae) let them twist through flooded forests of the Amazon Basin. Locals weave legends about shape-shifting botos transforming into handsome men to seduce villagers: a myth as haunting as the river dolphin’s smiles.
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Sperm whale
The sperm whale is famous for its size – males can exceed 18 meters – but their massive square heads are particularly odd. Nearly one-third of a sperm whale body length, the head houses the spermaceti organ, a waxy structure that generates powerful echolocation clicks and is also thought to help with buoyancy. These whales dive deeper than 2,000 meters and for periods of an hour or so to hunt giant squid, making them one of the most extreme predators on Earth.
Irrawaddy dolphin
Part dolphin, part cartoon character, the Irrawaddy dolphin looks almost unfinished: a rounded forehead, no beak and a perpetual half-smile.
Found in coastal waters and some freshwater rivers in Southeast Asia, these dolphins are remarkably shy and slow, often swimming in pairs rather than large pods. They look a little like baby belugas and, like the beluga, they can move their lips and like to squirt water from their mouths into the air when socialising and fishing.
In some places such as Myanmar, fishers once worked cooperatively with Irrawaddy dolphins, signalling each other to corral fish.
It is one of the rarest dolphins in the world.
Beaked whales
If whales had a secret society, it would be the beaked whales. With at least 24 species, they’re some of the least-known mammals on Earth. Beaked whales are deep-diving specialists: the Cuvier’s beaked whale holds the record for the longest recorded dive of any mammal – over 3,600 meters deep and nearly four hours long. Their long snouts, bizarre jawlines and often only two visible teeth make them look prehistoric.
Beluga whale
Snow-white and highly sociable, the Arctic beluga whale is also called the 'sea canary' for its wide range of whistles, chirps and clicks. But the beluga's oddest trait is probably the melon – a fatty, rounded forehead that belugas can change in shape, squishing and bulging as they echolocate. Their gregarious nature and bizarre expressions make them one of the most charismatic, yet strangest, whales alive.
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Pilot whale
Pilot whales look like giant dolphins with bulbous foreheads, but their strangeness lies in their social structure. They live in tight-knit pods of hundreds, sometimes mass-stranding together in heartbreaking numbers. These whales demonstrate extreme loyalty, often refusing to abandon a sick or stranded podmate even if it risks their own lives: a behaviour that baffles scientists and evokes deep empathy.
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Hourglass dolphin
The hourglass dolphin’s striking appearance makes them look like they were created by a graphic designer. They prefer the cold and live in deep Antarctic and sub-Antarctic waters – in fact, they are the only small dolphin regularly found south of the Antarctic Convergence, the line where cold and warm water meets.
They are also very fast, incredibly boisterous and enjoy surfing on the waves created by boats. As well as being beautiful to look at, they create a lot of spray while travelling at the surface of the water.
Chinese white dolphin
Also called the Indo-Pacific humpback dolphin, this species is striking for having bubblegum-pink skin – a colour that intensifies with age (adults may be grey or white). Found around Southeast Asia, including near Hong Kong, their unusual hue comes not from pigment but from blood vessels close to the skin’s surface, which help with thermoregulation. Their playful leaps against urban backdrops make them one of the ocean’s most surreal sights.
They once lived along the coasts from China to southeast Asia and as far west as India, but are sadly vanishing from many regions due to human threats.
Bowhead whale
Living exclusively in the Arctic, the bowhead whale has an enormous, bow-shaped skull that can break through sea ice more than half a meter thick. But its weirdest trait isn’t physical – it’s temporal.
Bowheads are the longest-lived mammals on Earth, with some individuals estimated to be over 200 years old. In their lifetimes, they have can witnessed shifting ice ages, industrial whaling eras and climate change.
When one individual was killed by native Alaskan hunters in 2007, it still had an old whaling harpoon from the 1800s embedded in its flesh, indicating that the whale had survived another 100 years after being harpooned.
Why being weird matters
These unusual cetaceans aren’t just curiosities – they highlight the diversity of life in our oceans and rivers. Each strange adaptation, from melons to spiral tusks, reflects millions of years of evolutionary adaptation. They remind us that the sea is home to far more than common dolphins leaping at sunset or the mighty blue whale.
For science lovers, these weird and wonderful whales and dolphins are proof that nature is endlessly inventive. And for all of us, they’re a reminder that the oceans still teem with mysteries waiting to be understood – and protected.
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