The male duck-billed platypus (Ornithorhynchus anatinus) has venomous spurs located on its hind legs. When threatened, the animal will drive the spurs into the skin of a potential enemy, inflicting a painful sting. The venom released is relatively mild and generally not harmful to humans, but for most animals that try to bother the platypus, it makes them hesitate to attack the platypus again.