Wolves

From Tolkien Gateway
Wolf Riders by Guy Gondron.

Wolves were of old allied with the Dark Lord; Morgoth bred the two greatest of their kind, Draugluin and Carcharoth, and Sauron was wont to take the form of a great Wolf. The lesser kinds were sometimes used as steeds by the Orcs.

Wolf is also used as a short form of Werewolf.