Gervase of Tilbury, the 13th-century author of "Otia Imperialia", includes a good many pieces of fairy belief in Part III of that work, some of them English and some from other parts of Europe. The Grant seems to be a close relation of the hedley kow, the Picktree Brag and those other spirits whose most natural shape was that of a horse. He seems, however, to be a warning spirit and to be in character more like a banshee than like the dangerous and malicious kelpy or Each Uisge. Gervase explicitly places the Grant in England (1290: p.196):

There is in England a certain kind of demon whom in their language they call Grant, like a yearling foal, erect on its hind legs, with sparkling eyes. This kind of demon often appears in the streets in the heat of the day, or about sunset. If there is any danger impending on the following day or night, it runs about the streets provoking the dogs to bark, and, by feigning flight, draws the dogs after it, in the vain hope of catching it. This illusion warns the inhabitants to beware of fire, and the friendly demon, while he terrifies those who see him, puts by his coming the ignorant on their guard.

Thomas Keightley "The Fairy Mythology" (1290: p.196-197; 652: p.286)