No, a koala is a marsupial. This means it belongs to a group of mammals that includes the kangaroo. A marsupial bears live babies, but they are not ready to fend for themselves when they are born as they aren't fully developed (they are tiny and blind with no hair). So a marsupial has a pouch on her belly, and the baby lives inside this, where it is warm and it can drink the mother's milk. When the baby, or joey, is old enough (about 6 months in the case of koalas) it climbs out and starts to eat other food. In the last few weeks in the pouch, baby koalas still aren't able to digest the typical koala food, such as eucalyptus leaves, and during this last stage it is weaned on a soft food which basically comes from the mother's droppings.

Marsupial young also tend to remain dependent for longer than most mammals, and the young koala continues to climb back inside the pouch and drink milk until it gets to big to fit inside.