Lough Dubh, Roscommon
Lake Monster. In 1962 a creature was hooked by a man and his son whilst out fishing. Described as having "short thick legs with small ears and a white pointed horn on the snout. It was dark grey in colour, and covered with bristles or short hair, like a pig." It was said to be the size of a cow and aggressive.
Other sightings have may have been made in 1956 and 1960