The domovoi

The house spirit of Russian and Ukrainian folk belief, usually pictured as a hairy old man living behind or under the stove. In Ukraine he is the domovyk.

Jan Máchal, in a 1918 volume of The Mythology of All Races, says Russians call the domovoi Děduška Domovoy, meaning grandfather house-lord, and tell many stories about him. He is usually shown as old, with shaggy grizzled hair and flashing eyes, furred all over his body. He wears a long cloak tied at the waist with a pale red belt, or only a red shirt.

Máchal lists where he lives: behind the stove or beneath it, by the threshold, in a closet, the yard, the stable or the bath-house. In the bath-house he hides beneath the benches and hisses, rumbles and giggles, and people preparing a bath set out a pail of water so he can wash.

Wikipedia adds that he may take animal form, as a cat, dog or bear, or look like the householder or a dead ancestor of the family, sometimes with a tail and small horns. In some traditions he is pictured as a snake. The Encyclopedia of Ukraine lists the domovyk, the house demon, among the figures Ukrainian oral tradition kept until recently, next to the khovanets, a hider that protects the house and aids its owners but can also do harm.