The Beast Within
Lambs to the slaughter.
A lonely cottage hides a dreadful secret.
While searching for a place to make camp for the night, the party is drawn to a clearing by sound of bleating lambs and the smell of a wood fire. In the clearing is a rustic cottage and tethered around it are a dozen lambs, forming a ring around the house.
The owner is a reclusive cleric who contracted lycanthropy about a year ago when his camp was attacked by a marauding werewolf. Though he recovered from his injuries, on the next full moon he transformed and attacked his companions. In the aftermath he resigned himself to a life of isolation, believing that his faith will cure the curse.
This is a short adventure, just a single combat encounter where the werewolf attacks the party. If the werewolf isn't killed outright there is a roleplaying opportunity and the potential for the party to seek a cure.
Although the adventure is set in the Forgotten Realms campaign, it can be readily adapted to any setting.
Pgs. 66-69