Koalas are native to Australia, they are often called koala bears because they look like a bear. While they are mammals, koalas are not bears. In fact koalas are vegetarian marsupials.
It might seem like koalas would make good pets, they are cute, slow moving, and have a simple diet (they eat certain eucalyptus leaves). However koalas do not do well in captivity and there are laws against them being kept as pets.
Indeed there are many claims that koalas have a shorter lifespan in captivity than they do in the wild.
Koalas were, at one time, hunted to near extinction. In the early 1900′s their fur was in demand and millions were killed until public outcry halted the slaughter. In 1934 it was estimated that there were only a few hundred to a thousand koalas alive in the wild.
Today the koala species is strong, and there are several animals in zoos around the world. Good zoos where koalas are kept typically have their enclosures set up so the people can see the koalas, but the koalas cannot see the people.