Werewolf

Werewolves were creatures that could shapeshift from humanoid form to that of a wolf, voluntarily or otherwise.

Their condition was usually called lycanthropy. (TV: Mindwarp)

Legend
Werewolves were creatures that appeared human but tranformed into beasts in the light of a full moon. The bite of a werewolf would turn the victim into a werewolf. The Tenth Doctor and Rose Tyler speculated that this might have happened to Queen Victoria when they met her. (TV: Tooth and Claw)

Because they existed in myths, they were present in the Land of Fiction. The Cybermen converted them as woodsmen, but under the full moon they turned into monsters of plastic and flesh and fur. This showed the Cybermen the potential of converting other fictional creatures. (AUDIO: Legend of the Cybermen)

History
The universe was home to several types of werewolf.

During the Vampire Wars, the Time Lords created a race of lycanhtropic Gallifreyan soldiers to fight the vampires. They eventually deserted and settled in Greece in 1500 BC. (AUDIO: Brightly Shone The Moon That Night)

The Second Doctor encountered a werewolf in 3300 BC Italy. (PROSE: Loop the Loup)

The Tenth Doctor and Rose Tyler encountered a Lupine Wavelength Haemovariform in 1879 Scotland. (TV: Tooth and Claw)

In the early 1890s Henry Gordon Jago and George Litefoot defeated an army captain who had been bitten by a werewolf in India. (AUDIO:  The Bloodless Soldier)

In 1903, after receiving a wealth of information from the future, Grigori Rasputin saw werewolves. (AUDIO: The Wanderer)

Werewolves were apparently prevalent in pre-World War II Germany, where Emmeline Neuberger remembered being forcibly recruited by the government along with other werewolves as a death squad before she escaped to England, although she later reflected that her memories could have been altered by Hester Stanton. Emmeline helped the Eighth Doctor and Harry Sullivan prevent Hester's plan to take over the world, and may have turned Harry into a werewolf, but Harry was subsequently taken away by the Fourth Doctor and Sarah Jane Smith. The Eighth Doctor attempted to arrange help for Emmeline via his government contacts, but they held her prisoner to try and find a way to force the change until she was rescued by the Fourth Doctor (who would go back to rescue Harry in his future). During this time the Fourth Doctor learned how to force and reverse the change to trigger Emmeline's transformation and later turn her back, and it is possible that he was able to devise a permanent cure for Harry. (PROSE: Wolfsbane)

The First Doctor and Susan encountered a werewolf in 1963 and were put on trial after they killed it, forcing the Doctor's future selves to act as jurors to cast doubt on the case. (PROSE: The Juror's Story)

Iris Wildthyme and Edwin Turner encountered a werewolf in 1970s Flanders. (AUDIO: An Extraterrestrial Werewolf in Belgium)

UNIT may possibly have fought werewolves before or at least know about them, given that by the 1990s their arsenal contained, amongst other exotic armaments, silver bullets. (TV: Battlefield)

The Fifth Doctor and Turlough encountered Earth-based werewolves in 21st century Brazil, with these wolves so tied to Earth that they couldn't even ascend too high without being killed. (AUDIO: Loups-Garoux)

The Seventh Doctor and Ace met and befriended a Vulpanan werewolf named Mags in an era of space travel. Though good-natured, she had little control over her transformations. (TV: The Greatest Show in the Galaxy)

The Eighth Doctor, on a visit with Sam Jones to Saturnia Regina, encountered the Jax, a species thought extinct, who had in ancient times developed a virus controlled with technology that could turn people into werewolves. (PROSE: Kursaal)

Werewolf-like creatures
The Daleks employed the Werelox. (COMIC: Doctor Who and the Dogs of Doom)

Stahlman's ooze transformed some humans into degenerated humanoid creatures, the Primords. (TV: Inferno)

Biological experimentation turned Yrcanos's faithful servant into a vulpine humanoid known as the Lukoser. (TV: Mindwarp)

Windigo were similar in biological concepts to werewolves. (COMIC: Bad Blood)

Wardog, parahuman member of the Special Executives, affiliated to early Gallifrey, was considered a werewolf lookalike. (COMIC: Black Sun Rising)

On a distant planet, the Sixth Doctor and Charley discovered that the local creatures were essentially inverted werewolves, as they were wolf-like beings who turned into a primitive, feral humanoid in the day. (AUDIO: The Red House)