Given the areas likely to be settled and the (relitively) local avalibility of animals you're more likely to see ugly little ponies and buffelos introduced than camels.I guess you could see camels in Australia if Arab traders get there, find something of interest, and set up a settlement. They'll probably bring camels if they settle an arid area (most of the continent). Maybe the camels will go feral after the settlement is abandoned, and the aborigines domesticate and ride them. Implausible, but it'd do the trick.