Shigidi, or Shugudu, is deified nightmare. The name appears to mean "something short and bulky," and the god, or demon, is represented by a broad and short head, made of clay, or, more commonly, by a thick, blunted cone of clay, which is ornamented with cowries, and is no doubt emblematic of the head.
Shigidi is an evil god, and enables man to gratify his hate in secret and without risk to himself. When a man wishes to revenge himself upon another he, offers a sacrifice to Shigidi, who thereupon proceeds at night to the house of the person indicated and kills him. His mode of procedure is to squat upon the breast of his victim and "press out his breath;" but it often happens that the tutelary deity of the sufferer comes to the rescue and wakes him, uponwhich Sbigidi leaps off, falls upon the earthen floor, and disappears, for he only has power over man dur ing sleep. This superstition still lingers among the negroes of the Bahamas of Yoruba descent, who talk of being "hagged," and believe that nightmare is caused by a demon that crouches upon the breast of the sleeper. The word nightmare is itself a survival from a similar belief once held by ourselves, mare being the Anglo-Saxon mære, elf or goblin.
The person -who employs Shigidi, and sends him out to kill, must remain awake till the god returns, for if he were to fall asleep Shigidi would at that moment turn back, and the mission would fail. Shigidi either travels on the wind, or raises a wind to waft him along; on this point opinions differ. The first symptom of being attacked by Shigidi, is a feeling of heat and oppression at the pit of the stomach, "like hot, boiled rice," said a native. If a man experiences this when he is falling asleep, it behoves him to get up at once and seek the protection of the god he usually serves.
Houses and enclosed yards can be placed under the guardianship of Shigidi. In order to do this a hole is dug in the earth and a fowl, sheep, or, in ancient times with exceptional cases, a human victim was slaughtered, so that the blood drains into the hole, and is then buried. A short, conical mound of red earth is next built over the spot, and an earthen saucer placed on the summit to receive occasional sacrifices. When a site has thus been placed under the protection of Shigidi, he kills, in his typical manner, those who injure the buildings, or who trespass there with bad intentions.
*culled from www.awonifa.com