She-demon

If some were akin to the Formori of the baleful fogs in Irish mythic history and the Mallt-y-nos, those she-demons of marshy lands immortalised by the Welsh bards, creatures huge and uncouth "with grey and glaring eyes," there were others who exceeded in beauty anything human.

When night had fallen, the she-demon stole forth toward the hall, which she entered unheard and unseen.