The official GemStone IV encyclopedia.
A rodent-like creature with a small head and distinct ears, its head covered with a fine textured short fur. The undertaker bat's leathery wings outstretch to three times its body length, with its skeletal features visable through its black skin. Small fangs protrude beyond its closed mouth.
1) They have a shriek attack with a hidden role that hits everyone in the room and can cause a long RT. (Have seen 20 seconds.)
2) If they hit with you their physical attack, it can inflict a fast-acting disease. Make sure to carry a way to cure disease or rapidly heal HP.
An undertaker bat opens its mouth and releases an ear-splitting high-pitched tone!
A stinging pain pulses in your ears, causing you to bring your hands to your head in an effort to regain your presence of mind!
Roundtime: 13 sec.