The Morrigan

In the Religious Beliefs of the Pagan Irish, by O'Beirne Crowe, is a reference to the Morrigan, which once appeared in the shape of a bird "addressing the famous bull Dond in dark mysterious language."—"On another occasion she appears to Cu, in the form of a beautiful lady, and tells him she is in love with him, and has brought him her gems and her cattle. Cu said he had something else than love to attend to at that time. She said when he would next engage in single combat, she would, in the shape of a serpent, coil herself around his feet, and hold him fast for his adversary."