A marsupial is a type of mammal that carries its babies in a pouch. When a marsupial is born, it's tiny, hairless, and barely developed, about the size of a jellybean. The newborn crawls into its mother's pouch, where it stays safe and warm while it continues growing, drinking milk and developing for weeks or months until it's ready to explore the world.

Kangaroos are the most famous marsupials. A baby kangaroo, called a joey, spends about six months in its mother's pouch before hopping out. Koalas, wombats, and opossums are also marsupials. Most marsupials live in Australia, though opossums live throughout North and South America.

Scientists classify marsupials as a special group of mammals because of how they raise their young. While most mammals (like humans, dogs, and whales) develop inside their mother's body before birth, marsupials take a different approach: they're born early and finish developing in the pouch instead.

The Tasmanian devil, sugar glider, and even the extinct thylacine (Tasmanian tiger) were all marsupials. Each species has adapted its pouch and parenting style to fit its environment and lifestyle.