1. Inland Taipan
The inland taipan (Oxyuranus microlepidotus), the small-scaled snake, or the fierce snake,is an extremely venomous snake of the taipan , and is endemic to semi-arid regions of central east Australia.
2. Eastern Brown Snake
The eastern brown snake is considered to be the second most venomous terrestrial snake. The venom has a SC LD50 range of 36.5 μg/kg and consists mostly of neurotoxins (pre- & post-synaptic neurotoxins) and blood coagulants. These snakes kept at venom supply laboratories yield an average of 210 mg of venom per milking. Engelmann and Obst (1981) give a venom yield of 2 mg (dry weight). As with most venomous snakes, the volume of venom produced is largely dependent on the size of the snake. Worrell (1963) reported a milking of 41.4 mg from a relatively large 2.1 metres (6.9 ft) specimen. This record is atypical, as the eastern brown snake yields a low volume of venom which is reported as not more than 10 mg, averaging only 2 mg (dry weight).
Clinically, the venom of the eastern brown snake is known to cause diarrhea, dizziness, collapse or convulsions, renal failure, paralysis and cardiac arrest. Without medical treatment, bites can be fatal. As this species tends to initiate their defence with non-fatal bites, the untreated mortality rate in most snakebite cases reported is 10–20%, which is not very high.
In mice, the IV LD50 for this species is 0.1 mg/kg. Blue Krait's venom is lethal 50% even after administration of antivenom; without antivenom it is 70% lethal for humans.
4. Black Mamba
The black mamba (Dendroaspis polylepis), also called the black-mouthed mamba, is a highly venomous snake of the genus Dendroaspis (Mambas), and is endemic to sub-Saharan Africa.
5. Tiger Snake
Tiger snake venoms possess potent neurotoxins, coagulants, haemolysins and myotoxins. Symptoms of a bite include localized pain in the foot and neck region, tingling, numbness, and sweating, followed by a fairly rapid onset of breathing difficulties and paralysis. In a study, the untreated mortality rate from its bites is reported to be between 40 and 60%.