With the finesse of a fly-fisherman, the spider-tailed horned viper lures its feathered prey to its doom.

The spider-tailed horned viper is a venomous snake that inhabits a small area in western Iran. Scientists first discovered it in 1968 but thought the tail was a random mutation. Yet, it was 2006 before scientists had a live specimen to examine and determined that the unique tail indicated they had a new species.

Spider-Tailed Horned Viper Amazing Facts

• The species uses a caudal lure (the tail!) that looks like a spider – a phenomenon known as feeding mimicry.
• These vipers blend into their environment well enough that birds land on them, so focused on the “spider” that they do not see the snake until it’s too late.
• They can strike in .2 seconds.
• Many of the local birds have figured out the viper’s game – it appears that only the visiting birds fall prey to its charms.

Spider-Tailed Horned Viper Location

They have only been found in a few areas in western Iran and are rare enough that CITES agreed to add them to Appendix II to restrict international trade. 

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Spider-Tailed Horned Viper Scientific Name

The spider-tailed horned viper, or Pseudocerastes urarachnoides, is part of the Viperidae family and means false horned, spider-like tail. Vipers are a family of venomous snakes with retractable fangs that inject venom deep into their prey. They are present in most parts of the world except Siberia, Ireland, the arctic circle, and Australia.

Pseudo = false

cerastes = false

ura = tail

arachna = spider

ides = like

Spider-Tailed Horned Viper Population & Conservation Status

The IUCN listed it as “data deficient” because there isn’t enough data to determine whether they are threatened or endangered. Its range is small enough that there’s a concern among the scientific community. Scientists seek more information and want to have a more detailed study done. 

Appearance & Description: How to Identify the Viper

These vipers are unique-looking. Their eyes are tan-colored with vertical pupils. They have rough skin with keeled scales that blends well with the granite of their home range; and scales that extend upwards from the eyes, forming “horns.” Their most unique feature is their tail: they have a bulbous, fleshy-looking end with long, thin scales that dangle from it. 

Photos & Videos of the Spider-tailed Horned Viper

Video showing the viper catching a bird, using its tail as a lure.

Venom: How Dangerous is a Spider-tailed Horned Viper?

It is venomous and will strike when threatened. However, it doesn’t seem to be aggressive towards people unless cornered.

Behavior & Humans

This viper is an ambush predator with a twist. It wiggles the end of its tail, making it appear alive. Its favorite food is of the feathered variety, and several videos show a spider-tailed horned viper luring a bird close enough to strike. However, it doesn’t restrict its diet to birds – the spider-tailed horned viper also hunts arthropods, rodents, and lizards.

People have become its most significant predators, and its unique hind end has attracted collectors.

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