The Cailleach is the Queen of the Winter. In her highland cave, she imprisons the Maiden of Spring who, fortunately, always manages to escape, even if she is a little later in succeeding some years than others, and brings with her the first signs of Spring, celebrated at the Celtic festival of Imbolc. The Cailleach does not completely lose her power until Beltane (around 1st May) at which time she hides her staff under a gorse bush or holly bush and turns to stone. You must have noticed these single standing stones, solitary in fields or on heathland. At Samhain (November), the Cailleach is reborn and, taking up her staff again, she stalks the earth, frosting plants and bringing snow.
She is easily recognisable from her blue face and single eye but, like so many others of these ancient gods and goddesses, she is a shape changer and can appear as a beautiful woman to deceive the unwary.