And to add to the Australian Creatures thing,
Koalas eat the leaves off of the trees.
Kangaroos can jump up really high, and when aggrivated, put on boxing gloves and attack you.
Bearded Dragons could hide "in" the sand. After walking on the block they're hidden in, they spring out, ready to attack. You could tame them with Pork, and the more you feed them, the bigger they get.
