The Morrigan next came in the form of a rough, grey-red bitch-wolf [and she bit Cuchulain in the arm and drove the cattle against him westwards, and Cuchulain made a cast of his little javelin at her, strongly, vehemently, so that it shattered one eye in her head.] During this space of time, whether long or short, while Cuchulain was engaged in freeing himself, Loch wounded him through the loins. Thereupon Cuchulain's anger arose within him and he wounded Loch with the Gae Bulga ('the Barbed-spear'), so that it passed through his heart in his breast. http://www.sacred-texts.com/neu/cool/cool15.htm
Although the Morrigan is often though of as having a conection with ravens most commonly in this case she takes the form of a wolf. In other places in the Táin Bó Cúailnge she takes the form of other animals as well. But in this passage at least she is a wolf.
As I was walking all alane, I heard twa corbies making a mane, the tane unto the nither did day, What sall we gang and dine the day?