You’ve encountered a Banshee. This counts as a rare creature encounter for the purposes of levelling, but does not count as a Random Event for levelling or MP. There will be no further admin/re intervention. If you choose to follow this creature, you do so at your own risk, however, just having it in this thread is enough to satisfy your levelling requirements. You may not kill your rare creature without admin permission.
Banshees (rare/mythical): They take the form of a skeletal lady wrapped in rags. Some wander the woodlands, singing a haunting melody. Others sit near streams and weep. Either way, disturbing these creatures will cause them to become very aggressive. They can pursue their prey seemingly without need for rest, and will strangle all those that they catch.