Discover Thousands of Animals from A to Z

Panthera leo

The lion is one of the world's most recognizable big cats, known as the 'king of the jungle' despite living mainly on open savanna, and is the only cat species that lives in large social groups called prides.

Panthera tigris tigris

The Bengal tiger is the most numerous tiger subspecies, with India alone holding the large majority of the world's wild tiger population, and it is the largest wild cat native to Asia's forests, mangroves, and grasslands. Smaller populations also survive in Bangladesh, Nepal, and Bhutan, including in the Sundarbans, a vast mangrove delta shared by India and Bangladesh where tigers are unusually strong swimmers and sometimes hunt aquatic prey. India launched Project Tiger in 1973 to protect the subspecies through a network of dedicated reserves, and the country's wild tiger population has grown substantially since, even as poaching for the illegal wildlife trade and habitat fragmentation remain serious ongoing threats.

Loxodonta africana

The African elephant is the largest living land animal, roaming savannas, forests, and semi-arid regions across sub-Saharan Africa in tightly-bonded matriarchal herds. This entry refers specifically to the African bush elephant, the larger of two African species recognized by the IUCN since 2021 — the other, the African forest elephant, is smaller, has straighter tusks, and lives in the dense rainforests of Central and West Africa. Elephant populations were decimated by ivory poaching through the 20th century, and though international trade bans and anti-poaching efforts have slowed the decline in many regions, habitat loss and human-wildlife conflict continue to threaten the species today.

Ailuropoda melanoleuca

The giant panda is a bear native to a handful of mountain forest ranges in central China, primarily in Sichuan province, famous worldwide for a diet made up almost entirely of bamboo despite retaining the short digestive tract of a carnivore. Because that digestive system extracts relatively little energy from tough, fibrous bamboo, pandas must eat enormous quantities to survive, spending up to 12 hours a day feeding and consuming as much as 38kg of bamboo in a single day. Long a symbol of Chinese culture and a fixture of international 'panda diplomacy,' the species was reclassified from Endangered to Vulnerable by the IUCN in 2016 after decades of habitat protection and captive-breeding programs helped stabilize its wild population — one of conservation's clearer recent success stories, even as bamboo forest fragmentation remains an ongoing threat.

Tyrannosaurus rex

Tyrannosaurus rex was one of the largest land predators to ever exist, dominating the ecosystems of western North America at the very end of the Cretaceous period roughly 66-68 million years ago.

Phascolarctos cinereus

The koala is a tree-dwelling marsupial native to Australia, spending nearly its entire life in eucalyptus trees on a diet that would be toxic to most other mammals.

Acinonyx jubatus

The cheetah is the fastest land animal on Earth, built for explosive short sprints across the open grasslands and semi-desert of Africa, with a small, remnant population also surviving in Iran. Its speed comes at a genetic cost: cheetahs went through a severe population bottleneck thousands of years ago, leaving today's cheetahs with unusually low genetic diversity, which makes the species more vulnerable to disease on top of the threats it already faces from habitat loss and human-wildlife conflict.

Ursus maritimus

The polar bear is the largest land carnivore on Earth, superbly adapted to hunting seals across the sea ice of the Arctic Circle.

Danio rerio

The zebra danio is a small freshwater fish native to streams and rice paddies across South Asia, named for the five uniform, horizontal blue stripes running along its silvery body. Beyond its popularity as an aquarium fish, it has become one of the most important model organisms in modern biological and medical research.

Thunnus albacares

The yellowfin tuna is a large, fast-swimming fish found in tropical and subtropical waters across the world's oceans, prized both as one of the ocean's most powerful predators and as one of the most commercially important fish species for human consumption. Its name comes from the bright yellow coloring of its dorsal and anal fins, which become especially long and dramatic in mature adults.

Pristella maxillaris

The X-ray tetra is a small freshwater fish native to slow-moving rivers and streams in South America, named for its almost completely transparent body that reveals its skeleton and internal organs. Its see-through appearance has made it one of the most recognizable and popular small fish in the freshwater aquarium hobby worldwide.

Gulo gulo

The wolverine is the largest land-dwelling member of the weasel family, a solitary and famously tenacious predator and scavenger of far northern forests and tundra. Despite its bear-like appearance, it is much smaller than its reputation suggests, roughly the size of a medium dog, but is capable of driving much larger animals like wolves away from a carcass.

Phocoena sinus

The vaquita is the world's smallest and most endangered cetacean, found only in a small area of the northern Gulf of California in Mexico. Fewer than a handful of confirmed individuals are believed to remain in the wild, making it one of the most critically threatened marine mammals on Earth.

Cephalopterus penduliger

The umbrellabird is a striking rainforest bird named for the umbrella-like crest of feathers that arches forward over its head, along with a long, inflatable wattle of feathered skin hanging from its throat. Males use both features in elaborate courtship displays, along with deep, booming calls that can carry through dense forest.

Triceratops horridus

Triceratops was one of the last non-avian dinosaurs to exist before the mass extinction event 66 million years ago, instantly recognizable by the massive bony frill extending from the back of its skull and the three prominent horns on its face. It lived across what is now western North America, sharing its environment with predators like Tyrannosaurus rex.

Ambystoma tigrinum

The tiger salamander is one of the largest land-dwelling salamanders in North America, named for the yellow or olive blotches and stripes marking its dark body. Most of its life is spent hidden underground in burrows, either ones it digs itself or ones abandoned by other animals, only emerging at night or during its brief breeding season.