DLC name: Of Wolf And Man
A werewolf has been killing travellers, bandits and townsfolk as well as live stock, horses and local wild life in the game world. The head of one of the towns says he'll pay you a substantial amount of gold if you can hunt it down, kill it and produce its head to him.
The werewolf only hunts at night and, like dragons, will appear randomly throughout the game world. Its your job to investigate the mauled bodies, claw and teeth marks it has left behind as well as speaking to local people about where it has attacked so that you can search for it close by.
ALTERNATIVE OUTCOME: While investigating a nearby cave during the day time you find a man cowering near a rock in torn clothes covered in blood. It turns out that this guy is actually the werewolf (this man will always hide in caves during the daytime so depending on where it has attacked at night, it will be likely he is in a cave in that area during the day) and you can choose to kill him there or take him back to his father (the town's head who sent you on the quest in the first place) who straps him down and brings in the local witch doctor to remove the curse. However during the ritual some of the werewolf curse is transferred to you. This gives you the Call Of The Wolf ability which means that wolves will no longer attack you and you even have the ability to call on their assistance during a battle.
This alternative outcome is conditional on you finding the man during the day time. If you encounter the werewolf at night then you simply need to kill it and produce the head for the substantial gold reward.