Purple-necked Rock Wallaby

The purple-necked rock-wallaby (Petrogale purpureicollis) is a species of rock-wallaby first described in 1924 by Albert Sherbourne Le Souef, then director of the Taronga Zoo in Sydney, Australia, who noted a purple colouration around the neck and cranial features that distinguish it from other rock-wallaby species.

The purple colouration was thought by some sceptical scientists to be due to the animal rubbing against a dye, but the animal does in fact secrete a purple pigment. The pigment is known to wash off in the rain and fade away after death, causing some possible confusion with other rock-wallaby species.