Defining “tallest” gets complicated when you leave dry land. While animals like giraffes and elephants are measured by how high they stand, marine species such as whales and jellyfish challenge the scale with extraordinary body length.
This list brings together some of the planet’s most impressive giants – whether they tower above the treetops or extend far beneath the waves. Just be warned: not all height is vertical.
Tallest (and longest) animals
Blue whale
The blue whale is the biggest animal ever known to have lived on Earth, clocking up to 33 metres in length – and matching its length with a whopping 180,000kg in weight for females, and 150,000kg for males. Blue whales hold another impressive record, with the biggest penis – extending up to three metres in length.
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Giraffe
Standing at around four to five metres high, giraffes are the tallest mammals in the world. In fact, some giraffes have been recorded at heights of up to 5.9m – taller than a double-decker bus. Much of this height is found in their long necks, which help them reach high tree branches to feed.
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Saltwater crocodile
The male of the species is around five metres in length (although females are significantly smaller), making this deadly predator one of the longest reptiles. Snakes such as the reticulated python and green anaconda are longer in length, but the saltwater crocodile is generally larger. Historically, saltwater crocodiles of up to seven metres in length were likely to have existed, but these have been threatened due to hunting practices.
Lion’s mane jellyfish
Small in body but long in tentacle, the Lion’s mane jellyfish can grow up to 30 metres – using its long stinging tentacles to capture prey from far away and pull it in to eat. It's the biggest jellyfish in the world.
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Brown bear
Many species of bear are tall when standing on their hind legs, particularly polar bears and brown bears, which are the biggest bear species. Polar bears tend to be larger than brown bears, but brown bears are more variable in size – and can reach around three metres when standing on their hind legs. They have broad bodies, and they put on weight to prepare for hibernation.
Whale shark
Whale sharks are the largest species of shark and fish on Earth, reaching up to 20 metres in length. Despite their vast size, they are gentle giants, not generally aggressive towards humans and considered harmless. They filter seawater to feed on plankton.
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African elephant
The heaviest land animal on Earth, the African elephant can grow to between three and four metres tall, with males typically being larger than females. Their height and trunk length allows them to access a wide range of food sources. (Elephants also have the biggest noses in the animal kingdom).
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Ostrich
At 2.7 metres tall, the ostrich is the largest flightless bird – and the biggest bird in the world (weighing as much as a piano). They might be flightless, but ostriches are speedy on the ground – with running speeds of up to 40mph. This is partially down to their powerful, long legs.
Moose
The largest extant species in the deer family, moose are tall, heavy and with broad antlers. They generally measure between 1.5 and 2 metres tall.
Indian elephant
The Indian elephant is one of three species of Asian elephant, and tends to be between two and three metres tall at shoulder height. They are smaller than their African counterparts, but still taller than many other land mammals.
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