Wonambi

Wonambi is a genus that consisted of two species of very large snakes. These species were not pythons, like Australia's other large constrictors of the genus Morelia, and are currently classified in the extinct family Madtsoiidae. This genus was a part of the extinct megafauna of Australia

Diversity
The type species is Wonambi naracoortensis, a five to six metre long snake; the only other known species is Wonambi barriei.

Description
Wonambi seems to have been an ambush predator. Rather than using venom, the animal would kill its prey by constriction. The head of the animal was small, restricting the size of its prey.