Lake Muskry was formerly known as , but has also been known as . There is a folk tale of a serpent that was killing livestock on the Galty Mountains being banished by Saint Patrick and confined to Lake Muskry. According to the tale, Saint Patrick chained the serpent under the lake and promised to release the creature on , which the serpent mistook as . The serpent comes up each Easter Monday and asks Is it the Monday morning yet Patrick? and Patrick says No, and the serpent goes down again for another year. The same legend is also associated with Lough Dihneen, below Galtybeg. The belief in the serpent under Lough Dihneen was held so strongly that a Captain Dawson, a local landlord, attempted to drain Lough Dihneen in the 1830s to kill the serpent.