Maenads (also know as Bacchantes) were women (ok, i know, not creatures, but still) incited into religious frenzy by Dionysus. They left their homes and roamed wild around the countryside. Each carried a special staff known as a thyrsus. Maenads were so liberated from normal human conventions that they ripped apart live animals with their bare hands and ate raw flesh.
The Encyclopedia of World Mythology ed. Arthur Cotterell