Depicted as a veiled hag or an old crone, with one eye and deathly pale skin, she is said to have a bow-legged leaping gait, striding across mountains with a power to shape and transform the landscapes as rocks fall from her gathered apron. 
The Cailleach is the goddess of the winter months and is said to control the weather and the winds as well as the length and harshness of winter. Her season begins on October 31st, the Samhain festival, which we celebrate today as Halloween.
She was a complex character, neither fully good nor evil, caring for animals during the dark winter months and was the patron of wolves. She is also known to safeguard deer and have particular affinities for black cats, wild cattle and goats.
The word Cailleach comes from the "caillech" meaning "veiled one" in Gaelic. This word is the base root of many other words to describe women, such as the contemporary Irish word "cailin" meaning "girl".