Lycanthropy is a disease that causes the victim to transform into a were-creature and is generally contracted by being bitten by a pre-existing one. All races can contract lycanthropy; however, Argonians and Bosmer are somewhat resistant because of their racial resistance to disease.
Lycanthropy itself was created by Hircine, who now serves as the guardian of the people infected with lycanthropy. This disease gives the infected a bloodlust, meaning they must kill every time they transform. It is believed that a cure for this disease exists in the Glenpoint foothills of High Rock.
A common misconception is that the form a person takes upon contracting lycanthropy varies according to their species. Although a particular type of lycanthrope is more common in a certain province, there is no evidence to suggest the type is solely based on the race of the afflicted.
- Werewolves are the most common form among men, mer and extremely rarely, beastfolk. They can be found in all areas of Tamriel, particularly Skyrim.
- Werebears can be found in Solstheim and purportedly in Skyrim, however by the Fourth Era there is no sign of them.
- Wereboars are located exclusively in High Rock.
- Werevultures are reportedly rare in Valenwood.
- Werelions can be found in the jungles of Elsweyr.
- Werecrocodile are known to lurk in isolated swamps of Black Marsh.
- Weresharks are said to roam the seas, but little is known about them.
These certain types of lycanthropy can be found mainly in their originating homelands, however partial amounts of the creatures can be seen in neighboring provinces.
- The term "Lycanthropy" is incorrectly used to refer to any sort of were-creature instead of solely werewolves. Lycanthrope comes from the Greek "lykos" meaning wolf and "ànthrōpos" meaning human. The correct term is therianthropy. This semantic error is acknowledged and explained in the book On Lycanthropy: "Because the werewolf is the most ubiquitous of lycanthropes, the term lycanthropy has been used since ancient days to describe the disease that transforms men into half-beast, although lycanthrope only strictly should refer to men who change into werewolves."
- Though the existence of weresharks have been recorded within the lore of Tamriel, it is unknown how and who would turn into a wereshark. Furthermore, it is unclear how one would actually manage to contract this strain of lycanthropy in the first place, as sharks are water-borne, and most, if not all, humanoid races of Tamriel roams the land.