Arctic foxes have compact bodies, small ears, short noses, and legs to minimize heat loss. They have thick fur on their feet, hence the name "lagopus" (rabbit foot).
There are two types of Arctic lemmings with powerful digging claws, thick teeth, and large guts, adapted to eat low-quality food. Their lack of agility is offset by their toughness in the high Arctic.
Bison thrive in the harsh Great Plains winters with short legs, thick wool, and strong necks to forage in deep snow. Their insulating coats allow them to endure extreme cold.
Arctic hares have long legs, a powerful heart, and excellent camouflage. They have shorter ears, smaller noses, and fattier skin to conserve heat and can dig to stay warm.
Snowy owls have dense feathering, including on their feet, providing excellent insulation. They are expert hunters, primarily feeding on lemmings to sustain their energy needs in the Arctic.
Reindeer, classic tundra animals, have furry feet to avoid freezing and adapt quickly after birth. Newborns can walk, jump, and swim shortly after being born, adjusting to harsh environments.
Arctic terns avoid extreme cold by migrating to the opposite pole. Adapted for long-distance flight, they have large lungs and efficient muscles, allowing them to cover vast distances.
Polar bears are apex predators in the Arctic, with waterproof fur and wide paws for swimming and walking on snow. Their enormous size helps conserve heat, and they thrive on a diet of walruses.
Leopard seals, top predators in Antarctica, have thick blubber and increased myoglobin for deep dives. They primarily feed on penguins and are highly efficient swimmers.
Penguins are superbly adapted to Antarctica's cold, with veins that keep arterial blood warm, insulating feathers, and a unique fatty pouch for their eggs.