Wolf

The wolf was a predatory mammal on Earth and Marinus. It was similar to the domesticated dog.

Timber wolves (DWN: Doctor Who and the Keys of Marinus) on Marinus ranged in packs of twenty. In cold winters they grew hungry and sometimes raided villages at night. The scent of raw meat could attract them from miles away. Ian Chesterton and Altos were pursued by a pack of these wolves after, unknown to them, Vasor gave them a bag of raw meat. Vasor claimed to have once broken a wolf's back with his bare hands. (DW: The Keys of Marinus)

Wolves played a significant part in human culture. In Norse mythology, Fenric (or Fenrir, or Fenris) was a monstrous wolf which would, during the final battle between gods and beasts, would kill Odin and help destroy the world at the end of time. The people Fenric manipulated into freeing him were called the Wolves of Fenric. (DW: The Curse of Fenric) Other evil wolves included the Big Bad Wolf. (DW: The Unquiet Dead)

Wolves were natural predators of sheep. The Seventh Doctor and Ace once saw a wolf take a way a sheep that it had killed, near the Welsh village of Llanfer Ceiriog. (NA: Cat's Cradle: Witch Mark) So strong was the association between wolves and sheep that they were often suspected when dead sheep started appearing. In a small English village in 1936, villagers then went to far as to suspect that Harry Sullivan had actually changed into a wolf in order to kill a number of local sheep. (PDA: Wolfsbane)