The Museum of Sorcery and Witchcraft Tilberi. Very few women were involved in Icelandic sorcery and magic. One of the few tasks solely for women was to make and use a tyberi. A woman had to steal an human rib fom a churchyard on Whitsunday, wrap it in gray wool, and keep it between her breasts. The next 3 times she takes communion she must spill the wine over the bundle. The third time, the tyberi will come to life and grow too large to be hidden in her bosom. She must cut a piece of skin from her inner thigh to make a nipple which the tyberi will hang on to draw nourishment from her body fluids.