The most deadly spider on the planet, the Australian Funnel Web.
One bite from this spider is enough to kill a small child in under 5 minutes.
An antivenene has only been available for a number of years and has been the result of the work of the late Eric Worrel at his Wildlife park in Gosford NSW.
Found mostly in the Sydney area and the North Coast of NSW it likes to live in cool damp areas.

http://www.onset.unsw.edu.au/issue2/Crikey/crikey.htm