The wulver kept to itself and was not aggressive if left in peace. Unlike most werewolves the Wulver is not a shapeshifter and is not, nor was it ever, a human being. It appears to be a sort of immortal spirit. Jessie Saxby, in Shetland Traditional Lore writes:
The Wulver was a creature like a man with a wolf's head. He had short brown hair all over him. His home was a cave dug out of the side of a steep knowe, half-way up a hill. He didn't molest folk if folk didn't molest him. He was fond of fishing, and had a small rock in the deep water which is known to this day as the "Wulver's Stane". There he would sit fishing sillaks and piltaks for hour after hour. He was reported to have frequently left a few fish on the window-sill of some poor body.
After researching folklore traditions gathered primarily from Gaelic areas of Scotland, an authority on congenital disorders, Susan Schoon Eberly, has speculated the tale of the wulver may have a basis in a human being with a medical condition; she suggests it may be Hunter syndrome.
- Bane, Theresa (2013), Encyclopedia of Fairies in World Folklore and Mythology, McFarland, ISBN 978-1-4766-1242-3
- Black, Ronald (2005), "Introduction", The Gaelic Otherworld: John Gregorson Campbell's Superstitions of the Highlands and Islands of Scotland and Witchcraft and Second Sight in the Highlands and Islands, Birlinn – via Questia Online Library, (Subscription required ())
- Eberly, Susan Schoon (1988), "Fairies and the Folklore of Disability: Changelings, Hybrids and the Solitary Fairy", Folklore, Taylor and Francis, 99 (1), JSTOR 1259568, (Subscription required ())
- Saxby, Jessie (1932), Shetland Traditional Lore, Edinburgh, Grant & Murray, ASIN: B000O9XQ6M
- Briggs, Katharine, An Encyclopedia of Fairies, Pantheon Books