Snake
Snakes were a variety of reptiles of the suborder Serpentes on Earth. They were often seen as fearsome and representative of evil.
A snake from Brazil was one of the animals on board the Ark. (TV: The Ark)
According to Greek mythology, Medusa had snakes for hair. (TV: The Mind Robber)
A type of giant snake was native to Metebelis III at some point in its history. (TV: The Green Death)
Styre's experiments on Sarah Jane Smith caused her to hallucinate a snake on her arm. (TV: The Sontaran Experiment)
The Fourth Doctor angrily referred to Calib as a "rattlesnake" for having stabbed Leela with a Janis thorn. (TV: The Face of Evil)
In the Arizona desert, the Tenth Doctor and Donna Noble encountered an alien which had mutated into a giant rattlesnake. (COMIC: Sting of the Serpent)
The Mara took the form of a giant snake. (TV: Kinda, Snakedance)
Giant purple Ice Snakes lived on Centuria. (COMIC: Enemy Mine)
The Church once fought Lava Snakes. (TV: The Time of Angels)
A giant species of snake called the Oroborus was able to consume time. (TV: Oroborus)
Another giant species of snake known as the Sythaks were native to the swamps of Palliox, a planet near Trion. In 1905, the travelling showman Thaddeus P. Wrinklemeyer had two Sythaks in his freakshow. (AUDIO: Freakshow)
Polly Wright was always afraid of snakes. (AUDIO: House of Cards)
