Koalas don't have tails
Koalas do not have external tails at all.
size? -Not only that, koala are not bears at all... they are marsupials.
A koala joey, when first born, is about the size of a kidney bean, and weighs approximatey half a gram. The koala then continues to grow, reaching almost adult size when it is about 12 months old.
It doesn't need one. The koala has extra padding on its backside to enable it to sit comfortably in the forks of trees. A tail would only get in its way.
A newborn koala is around the same size as a lima bean.
it is much big.
A koala
The only bear a koala looks like is a "teddy bear". The shape of a koala's face is quite different to that of bears. Its eyes are smaller and its nose is larger, though not in length. Koalas have no tail, unlike bears.
The weight of a koala joey is dependent upon its age. When first born, a koala joey weighs 0.5 grams. By the time the young koala is 13 weeks old, it weighs an average of 50 grams. As it grows, its weight naturally increases until, as an adult, a northern-dwelling male koala weighs up to 9kg (female 7.5kg) and a southern male koala up to 15 kg (females 9 kg).
No. A newborn koala joey is nowhere near the size of a mouse. In fact, even though adult koalas are very much bigger than adult mice, a koala joey when first born is about the size of a newborn baby mouse.
No. A newborn koala joey is completely hairless. It is about the size of a jellybean, and utterly helpless.