Werewolves are half-man, half-wolf. They appear to be normal humans until a full moon when they transform into monstrous beast that blindly attack anything and everything. One becomes a werewolf by being bitten by a wolf or werewolf. The disease it called Lycanthropy and to this date there is no known cure. Some ways to spot a werewolf are excessive hair, red hair, eyebrows joined in the middle, index and middle finger are the same length. The only way to kill a werewolf is with silver.
The Wolf’s Hour by Robert R. McCammon
Darker Than You Think by Jack Williamson
Twilight in the Towers by Clive Barker
Moon Dance by S.P. Somtow
The Tailsman by Stephen King & Peter Straub
The Wolf Man (1941)
Buffy the Vampire Slayer