1) Fierce Snake or Inland Taipan (Oxyuranus microlepidotus ), Australia. The most toxic venom of any snake. Maximum yield recorded (for one bite) is 110mg. That would porbably be enough to kill over 100 people or 250,000 mice. These rare snakes are vitually unknown in collections outside of Australia.
2) Australian Brown Snake (Pseudonaja textilis ), Australia. One 1/14,000 of an ounce of this vemon is enough to kill a person.
3) Malayan Krait (Bungarus candidus ), Southeast Asia and Indonesia. 50% of the bites from this snake are fatal even with the use of antivenin treatment.
4) Taipan (Oxyuranus scutellatus ), Australia. The venom delivered in a single Taipan bite is enough to kill up to 12,000 guinea pigs.
5) Tiger Snake (Notechis scutatus ), Australia.
6) Beaked Sea Snake (Enhydrina schistosa ), South Asian waters Arabian Sea to Coral Sea..
7) Saw Scaled Viper (Echis carinatus ), Middle East Asia.
8) Coral Snake (Micrurus fulvius ), North America.
9) Boomslang (Dispholidus typus ), Africa.
10) Death Adder (Acanthopis antarcticus ), Australia and New Guinea.
11) Black Mamba, both species of Green Mambas, and the Mojave Rattlesnake.

The factors include the individual’s health, size, age, and psychological state.  The nature of the bite may also vary, like penetration of one or both fangs, amount of venom injected , location of the bite , and proximity to major blood vessels. The health of the snake and the interval since it last used its venom mechanism is also important. These multiple variables make every bite unique. Depending on circumstances, the bite of a “mildly” venomous snake may be life-threatening and that of a “strongly” venomous snake may not.