Drashig

Drashigs were one of the most dangerous predators in the universe.

Biology
Drashigs are massive snake-like creatures with six eyes on stalks, fanged mouths, segmented bodies with greenish brown skin. They also have a sparse covering of hair. Their hide is strong enough to withstand machine gun fire. Especially large amounts of damage can kill them. They live in marshy areas. They are especially strong and can burst through metal structures. (DW: Carnival of Monsters)

Behavior
Drashigs are unintelligent but they are social. They hunt in packs of three and live in colonies of 20. When hunting or in pain, they emit a chilling scream. Drashigs can and will eat anything including most metals. They hunt by scent and they will never give up the hunt once they find a trail. When they encounter the Doctor the Drashigs pass him by and follow his scent back to the cave he came in. (DW: Carnival of Monsters)

History
When a battlethruster which had made an emergency landing on the Drashigs' satellite, Drashigs not only killed every one of the fifty person crew who had modern weapons but save for a few scraps of the reactor venticle, consumed the ship as well (although they prefer meat). A colony of Drashigs were kept in Vorg's Miniscope where the Doctor and Jo Grant encountered them. (DW: Carnival of Monsters) The Master's hypnosound device, which created fear-based illusions, Jo imagined she saw a Drashig. (DW: Frontier in Space). Using psychometry on the sonic screwdriver, Professor Herbert Clegg "saw" images of Drashigs. (DW: Planet of the Spiders)