The creature's nature was described by Walter Gregor, a folklorist and one of the first members of the Folklore Society, as "useful", "hurtful", or seeking "human companionship"; in some cases, kelpies take their victims into the water, devour them, and throw the entrails to the water's edge. In its equine form the kelpie is able to extend the length of its back to carry many riders together into the depths; a common theme in the tales is of several children clambering onto the creature's back while one remains on the shore. Usually a little boy, he then pets the horse but his hand sticks to its neck. In some variations the lad cuts off his fingers or hand to free himself; he survives but the other children are carried off and drowned, with only some of their entrails being found later. Such a creature said to inhabit Glen Keltney in Perthshire is considered to be a kelpie by 20th-century folklorist Katharine Mary Briggs, but a similar tale also set in Perthshire has an "each uisge" as the culprit and omits the embellishment of the young boy. The lad does cut his finger off when the event takes place in Thurso, where a water kelpie is identified as the culprit. The same tale set at Sunart in the Highlands gives a specific figure of nine children lost, of whom only the innards of one are recovered. The surviving boy is again saved by cutting off his finger, and the additional information is given that he had a Bible in his pocket. Gregorson Campbell considers the creature responsible to have been a water horse rather than a kelpie, and the tale "obviously a pious fraud to keep children from wandering on Sundays".