The eastern diamondback rattlesnake is a species of pit viper in the family Viperidae. The species is endemic to the Southeastern United States. It is one of the heaviest venomous snakes in the Americas and the largest rattlesnake. No subspecies are recognized.

The Gaboon viper, also called the Gaboon adder, is a viper species found in the rainforests and savannas of sub-Saharan Africa. Like all other vipers, it is venomous. It is the largest member of the genus Bitis, and has the longest fangs of any venomous snake – up to 2 inches (5 cm) in length – and the highest venom yield of any snake. No subspecies are recognized.