Phascolarctos cinereus (Koala), originally uploaded by Arthur Chapman.

Caption reads:

Koala – mother and baby (Phascolarctos cinereus) in the Tidbinbilla Nature Reserve near Canberra, ACT, Australia. Photographed on 29 September 1998.

While standing looking up the trees for Koalas, this mother and baby climbed down the tree – walked across in front of us – less than a meter away – and climbed up another tree nearby. An amazing sight.