Wolf

The wolf is a small mammal in the order Carnivora native to Earth. Humans domesticated wolves into dogs relatively recently.

Wolves (or wolf-like creatures) were also found on Marinus. (DW: The Keys of Marinus)

Wolves have played a significant part in Human culture. In Norse mythology, Fenric was described as a monstrous wolf which would, during the final battle between gods and beasts, destroy the world at the end of time. The people Fenric manipulated into freeing himself were known as the Wolves of Fenric. (DW: The Curse of Fenric) Other evil wolves included the Big Bad Wolf. (DW: The Unquiet Dead)

One of the prisoners of the Glass Prison was a woman known as the Wolf. (BFBS: The Glass Prison)

The Killorans seemed to be descended from wolves or wolf-like creatures. (BFBS: The Doomsday Manuscript)