The largest living snakes in the world, measured either by length or by weight, are various members of the Boidae and Pythonidae families.
The longest venomous snake, with a length up to 18.5–18.8 ft (5.6–5.7 m), is the king cobra,[1] while contesters for the heaviest title include the Gaboon viper and the Eastern diamondback rattlesnake.
[7] In spite of what has been, for many years, a standing offer of a large financial reward (initially $1,000 offered by U.S. President Theodore Roosevelt in the early 1900s,[8] later raised to $5,000, then $15,000 in 1978 and $50,000 in 1980) for a live, healthy snake over 30 ft (9.14 m) long by the New York Zoological Society (later renamed as the Wildlife Conservation Society), no attempt to claim the reward has ever been made.
[3] Although it is generally accepted that the reticulated python is the world's longest snake, most length estimates longer than 6 m (20 ft) have been called into question.
Moreover, the weight of wild specimens is often reduced as a symptom of parasite infestations that are eliminated by veterinary care in captivity.