One of the most enigmatic characters in all of Irish literature is the Morrígan. Alternatively described as a goddess, a trio of goddesses, a collective of battle spirits, and even a gloss for the Greek Furies, the Morrígan was known as a prophetess and a shapeshifter, appearing frequently in the form of a scald-crow.
When appearing as a trio of sisters, the three Morrígna are most commonly named as Morrígu, Badb, and Macha, although other names such as Fea, Anand, or Nemain are given in other sources. The name "Morrígan" itself may even have been seen as a title rather than a proper name, which was assumed by different figures at different times.
One of the Morrígan's most notable appearances is in the Táin Bó Regamna (the Cattle-Raid of Regamna), a prequel story to the better known Táin Bó Cuailgne. In the tale, the hero Cú Chulainn has an encounter with a strange, red-haired woman, whose presence is preceded by a terrible cry from the North. The woman, driving a chariot with a one-legged horse and accompanied by a man and a cow, tells Cú Chulainn that she is a satirist, and gives him a cryptic poem before transforming - chariot and all - into a black bird on a branch. Now recognizing the woman as the Morrígan, Cú Chulainn says he would have handled things very differently, had he known it was her. In response, the Morrígan tells him that misfortune would have resulted either way. Cú Chulainn insists that she has no power over him, to which she replies "I have power indeed; it is at the the guarding of thy death that I am, and I shall be," fortelling of Cú Chulainn's tragic fate, and the role she would play in bringing it about.