Hrm...
If I might add my (somewhat confused) two cents, I'd say you should try advertising for this in General chat, in one of the public maps to gauge interest. Especially if this is a less permanent kind of RP, I would suggest being more direct and simply asking around in-game for someone who'd be willing to play the role of prey.
Do that, and believe me, you'll have some wolf RP out there ready to hunt. xD