Argiope trifasciata (the banded garden spider or banded orb weaving spider) is a species of spiders found around the world. Generally seen hanging upside down in the centre of an orb web, with legs together in pairs. Trifasciatas are found throughout Australia around autumn. Often mistaken for the St Andrews Cross spider which is found in the east.
These awesome creatures are nearly completely harmless to humans and non-aggressive. When threatened, they responds either by dropping from the web or shaking it so vigorously that both spider and stabilimentum become a blur, confusing its attacker.
Fun Fact: Argiope is Latin for with bright face and trifasciata is Latin for three-banded.