Each werewolf has a compulsion or an obsession passed down to him or her from their werewolf parent or sire. It is carried by the aggressive mutation gene. These are referred to among english-speaking werewolves as "Callings," and are considered deeply personal and private aspects of a werewolf's personality.
Some werewolves will have stronger drive from their Calling than others, and some werewolves will have Callings which are - at least initially - directly opposed to what they see as their "nature." However, no werewolf would quite be who he or she is without their Calling. Most werewolves are very touchy about discussing something so integral to who they are and over which they occasionally have so little control. However, they are very much a part of life as a werewolf, and as a result it's important to have an idea of the basics.
Bonded's Calling: Your one true love is out there somewhere, and the ache to fill the void in your heart cannot be ignored.
Debtor's Calling: You are completely loathe to owe anyone anything, including favours.
Dominion's Calling: You are the paragon of werewolfness, and everyone had better recognize it.
Obsession Calling: You must pursue an absolute obsession, whatever that means for you. This may be with a hobby, a substance, a person, an ideal, or an activity, to name a few possible fixations.
Guardian's Calling: You must protect and defend friends and loved ones, even at the risk of losing your own life.
Mender's Calling: You are compelled to seek out those who are in need and aid them, even at cost to yourself.
Infection's Calling: You feel you must bite and infect as many humans as possible with the intent of turning them into werewolves. Presumably you'll feel better when there aren't any humans left, and it's nobody here but us wolves.
Judgment's Calling: Punish those who do evil, whatever that means to you, and probably to whatever extent you can get away with.
Lunatic's Calling: Sow chaos, generate entropy, upset the peace and the status quo. (Note: This is a 'wildcard' Calling that can be inherited from a werewolf of any Calling.)
Renown's Calling: You have a deep-seated need for recognition through fame or infamy.
Progenitor's Calling: Your biological clock is insistent that you reproduce and have/make children. Now. No, really. Now.
Seeker's Calling: Your keen mind and your big nose are well in agreement - you restlessly seek knowledge to apply to the survival of your pack.
Sentinel's Calling: You must protect the sanctity of your personal or pack's territory from intruders at all costs.
Slayer's Calling: You know what's a good idea? Kill all the humans. When they're out of the way, werewolves can run things.
Survivor's Calling: You place your own survival as the utmost top priority. Nobody and nothing else is more important than your own life.
Wanderer's Calling: You have a persistent urge to roam the earth, and are unable to stay in any one locale for too long.