List of largest snakes

The largest living snakes in the world, measured either by length or by weight, are various members of the Boidae and Pythonidae families. They include anacondas, pythons and boa constrictors, which are all non-venomous constrictors. The longest venomous snake, with a length up to 18.5–18.8 ft (5.6–5.7 m), is the king cobra,[1] and the heaviest venomous snake is likely to be the Gaboon viper (which also has the longest fangs and delivers the largest amount of venom) or possibly the Eastern diamondback rattlesnake – all three of which reach maximum weights in the range of 6–20 kilograms (13–44 lb).

There are eleven living snakes, listed below according to their maximum known or reported mass, that have a maximum mass that may reach or exceed 50 pounds (23 kg). Pending the acceptance of its taxonomic status, the Bolivian anaconda (Eunectes beniensis) may also merit inclusion, and the northern and southern variations of African rock python could be considered separately.

In terms of length, in addition to those listed here, there are two other species that may possibly reach a length of 20 feet (6.1 m) or more – the Oenpelli python (Morelia oenpelliensis) and the olive python (Liasis olivaceus) – however, the information available about those species is rather limited.[2] The Oenpelli python, in particular, has been called the rarest python in the world.[3][4][5]

It is important to be aware that there is considerable variation in the maximum reported size of these species, and most measurements are not truly verifiable, so the sizes listed should not be considered definitive. In general, the reported lengths are likely to be somewhat overestimated.[6] 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,[7] later raised to $5,000, then $15,000 in 1978 and $50,000 in 1980) for a live, healthy snake over 30 ft (9.1 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.[2]

Although it is generally accepted that the reticulated python is the world's longest snake, most length estimates longer than 6.35 m (20 ft 10 in) have been called into question.[6] It has been suggested that confident length records for the largest snakes must be established from a dead body soon after death, or alternatively from a heavily sedated snake, using a steel tape and in the presence of witnesses, and must be published (and preferably recorded on video).[6] At least one reticulated python was measured under full anesthesia at 6.95 m (22 ft 10 in), and somewhat less reliable scientific reports up to 10 m (33 ft) have appeared.[8]

Rank	Common name	Scientific name	Family	Mass	Image	Length	Range map
1	Green anaconda	Eunectes murinus	Boidae	May exceed 227 kg (500 lb),[9] validity questionable 97.5 kg (215 lb), reliable, maximum among 780 specimens caught over a seven-year period 1992–98[10] Average 30.8 kg (68 lb) among 45 specimens (1992–98)[10] Generally considered the heaviest		May exceed 8.8 m (29 ft),[9] not firmly verified[6] 5.6 m (18 ft), somewhat reliable[2] 5.21 m (17.1 ft), reliable, maximum among 780 specimens caught over a seven-year period 1992–98[10] Average 3.7 m (12 ft) among 45 specimens (1992–98)[10] Minimum adult length 3.2 m (10 ft)[2] Generally considered the second longest
2	Burmese python	Python bivittatus	Pythonidae	182.8 kg (403 lb), reliable, for "Baby" in 1998[6]		5.74 m (18.8 ft), reliable, for "Baby" ca. 1999[6] Minimum adult length 2.35 m (7.7 ft)[2]
3	Reticulated python	Malayopython reticulatus	Pythonidae	Up to 158 kg (350 lb), somewhat reliable[11][12] 158.8 kg (350 lb), somewhat reliable, for "Medusa" in 2011[13] Almost 160 kg (350 lb), somewhat reliable, for "Twinkie" in 2014[14] 136 kg (300 lb), somewhat reliable, for "Fluffy" in 2010[15] 133.7 kg (295 lb), reasonably reliable, for "Colossus" in 1954 (with an empty stomach)[6][16] 124.7 kg (275 lb), somewhat reliable, for "Samantha" in 2002[16][17] 59 kg (130 lb), reliable, wild specimen in 1999 (after not eating for nearly 3 months)[8]		10 m (33 ft),[11][12] not firmly verified[6] 7.9 m (26 ft), somewhat reliable, for "Samantha" in 2002[16][17] 7.67 m (25.2 ft), somewhat reliable, for "Medusa" in 2011[13] 7.3 m (24 ft), somewhat reliable, for "Fluffy" in 2010[13][15] 6.95 m (22.8 ft), reliable, wild specimen in 1999[8] 6.35 m (20.8 ft), reasonably reliable, for "Colossus" in 1963 (skeletal length)[6] Minimum adult length 3.04 m (10.0 ft)[2] Generally considered the world's longest
4	African rock python	Python sebae (sometimes considered two species, P. sebae and P. natalensis)	Pythonidae	Up to 113 kg (250 lb),[18] not firmly verified[6]		Up to 7.5 m (25 ft),[19] not firmly verified[6] Minimum adult length 2.50 m (8.2 ft)[2]
5	Indian python	Python molurus	Pythonidae	91 kg (200 lb),[20] not firmly verified[6] 52 kg (115 lb), reliable[21]		6.4 m (21 ft),[20] not firmly verified[6] 4.6 m (15.1 ft), reliable[21]
6	Amethystine (scrub) python	Simalia amethistina	Pythonidae	91 kg (200 lb) Little information about size is available[2][22]		Some reports up to[23] or exceeding 8 m (26 ft),[2] not firmly verified[6] 7.2 m (24 ft), somewhat reliable[24] In excess of 6 m (20 ft)[23] Typically 3.5 m (11 ft)[2] Minimum adult length 1.8 m (5.9 ft)[2] Little information about size is available[2][22]
7	Yellow anaconda	Eunectes notaeus	Boidae	They commonly weigh 25 to 35 kg (55 to 77 lb), though large specimens can weigh 40 to 55 kg (88 to 121 lb) or even more.[25]		4.6 m (15.1 ft), reasonably reliable[1][26] Typically 3–4 m (10–13 ft)[26] 3.1 m (10 ft) maximum among 86 specimens in a field study[27]	South America
8	Boa constrictor	Boa constrictor	Boidae	More than 45 kg (99 lb)[28]		Possibly up to 4.3 m (14 ft)[29] A much larger report was debunked[6][30]
9	Dark-spotted anaconda	Eunectes deschauenseei	Boidae	30 kg (66 lb)		3 m (9.8 ft),[31] validity unknown
10	Cuban boa	Chilabothrus angulifer	Boidae	27 kg (60 lb)[32]		4.8 m (16 ft)[32][33]
11	Papuan python	Apodora papuana	Pythonidae	22.5 kg (50 lb)[34] Little information about size is available[2]		One reasonably reliable report of 4.39 m (14.4 ft)[2][35] Often reaches 3–4 m (9.8–13.1 ft)[2] Most specimens 1.4–3.6 m (4.6–11.8 ft)[35] Little information about size is available[2]