The Platypus, with its duck bill and webbed feet, is a unique Australian animal. It and the Echidna are the only monotremes or egg-laying mammals to be found on earth, both found widely in Tasmania. The monotremes have lower body temperatures than other mammals and have legs which extend out, then vertically below them, resulting in a gait that resembles a reptilian waddle rather than a straight-line gait. These features, together with their egg-laying, are more like that of a lizard than a mammal. Platypus' are readily identified by their streamlined body, webbed feet, broad tail and characteristic muzzle or bill which is rubbery and contains no true teeth. Since platypus' dive repeatedly for food, they generally are only sighted when they briefly return to the surface to breathe. Then the top of their head, back and tail can be seen – like the tip of the iceberg, the rest remains submerged.
Echidnas, or spiny anteaters as they are sometimes known, are monotremes (mammals that lay eggs). There are only three species of monotreme in the world - the platypus and two species of echidna, one of which is restricted to the New Guinea highlands. Echidnas are 30 cm to 45 cm in length and weigh between 2 kg and 5 kg with Tasmanian animals being larger than their Australian mainland counterparts. The body, with the exception of the underside, face and legs, is covered with cream-coloured spines. These spines, which reach 50 mm in length, are in fact modified hairs. Insulation is provided by fur between the spines which ranges in colour from honey to a dark reddish-brown and even black. The fur of the Tasmanian subspecies is thicker and longer than that of echidnas in warmer mainland areas and therefore often conceals the spines.