In Orkney and Shetland, 'Booman' is a brownie-like hobgoblin. Its name is preserved elsewhere in singing games, 'Shoot, Booman, shoot', and 'Booman is dead and gone'. These are to be found in Alice Gomme's Dictionary of British Folk-Lore, Part I: Traditional Games (Vol.I, p.43).

The best-known of the Scottish water-horses. The Kelpie haunted rivers rather than lochs or the sea. He could assume human form, in which he appeared like a rough, shaggy man. In this shape he used sometimes to leap up behind a solitary rider, gripping and crushing him, and frightening him almost to death. Before storms, he would be heard howling and wailing. His most usual shape was that of a young horse. He played the ordinary bogy or bogey-beast trick of alluring travellers on to his back and rushing with them into a deep pool, where he struck the water with his tail with a sound like thunder and disappeared in a flash of light. He was suspected of sometimes tearing people to pieces and devouring them.

A picturesque version of the story of 'The Time is Come but not the Man' is told of the river Conan in Sutherland, in which the Kelpie seems to figure as the hungry spirit of the river. In his horse form, the Kelpie sometimes had a magic bridle. Grant Stewart in his Popular Superstitions tells how a bold MacGregor, nicknamed Wellox, took his bridle off the Kelpie. The Kelpie begged him to restore it, but he kept it and used it to work magic.

On the other hand, the man who put a human bridle on the Kelpie could subdue him to his will. Chambers tells us that Graham of Morphie once bridled a kelpie and used him to drag stones to build his new castle. When the castle was built he took off the bridle, and the poor, galled kelpie dashed into the river, but paused in the middle to say:

Sair back and sair banes

Drivin' the Laird o' Morphie's stanes.

The Laird o' Morphie'll never thrive

Sae lang as the Kelpie is alive!