Red-bellied black snake

(Pseudechis porphyriacus) Also known as the common black snake. Distributed down the east coast (though not to Tasmania) and slightly into south-eastern South Australia, also the Mt. Lofty ranges.

The red-bellied black snake is somewhat less venomous than many other Australian snakes, but you're more likely to come across it in urban areas and its bite is certainly no picnic, causing significant illness and requiring medical attention.

Red-bellied blacks are one of the few large venomous snakes still found in the Sydney region, and at 2m long are capable of eating other snakes. They are not particularly aggressive and will escape from humans if possible, but when threatened will flatten their bodies and hiss loudly.  The venom causes blood-clotting disorder and muscle and nerve damage, enough to knock you off your feet, but rarely deadly. No deaths have been confirmed from bites by this species.

See Paladian's snake blip from the same event.