Lesser Werewolf

Oracle Text

B: If Lesser Werewolf's power is 1 or more, it gets -1/-0 until end of turn and put a -0/-1 counter on target creature blocking or blocked by Lesser Werewolf. Activate this ability only during the declare blockers step.

Card Rulings

10/1/2009 You may activate Lesser Werewolf’s ability no matter what its power is. However, if Lesser Werewolf’s power is 0 or less at the time the ability resolves, the ability won’t do anything.