Wolf
The wolf was a predatory mammal on Earth and Marinus. It was similar to the domesticated dog.
Timber wolves (PROSE: Doctor Who and the Keys of Marinus) on Marinus travelled 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 had given them a bag of raw meat. Vasor claimed to have once broken a wolf's back with his bare hands. (TV: 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, in the final battle between gods and beasts, 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. (TV: The Curse of Fenric) Another evil wolf from Earth legends was the Big Bad Wolf. (TV: The Unquiet Dead, The Power of Three)
Wolves were natural predators of sheep. The Seventh Doctor and Ace once saw a wolf take away a sheep it had killed near the Welsh village of Llanfer Ceiriog. (PROSE: Cat's Cradle: Witch Mark) So strong was the association of wolves with sheep that they were often suspected when sheep turned up dead. In a small English village in 1936, villagers suspected that Harry Sullivan had actually changed into a wolf to kill local sheep. (PROSE: Wolfsbane)
In 2040, efforts were made to repopulate Europe with cloned wolves. (PROSE: Culture War)