f a woman wants to create a tilberi she has to dig up a human rib in a graveyard early on Whitsunday, tilberi1 wrap it in grey wool and preserve it between her breasts. The next three Sundays at communion she has to spit the holy wine on the bundle which will then come alive. Then the woman has to carve a nipple inside her thigh on which the tilberi will hang on and nourish itself.
en it is fully grown the woman can send it into the neighbouring pastures to steal milk from cows and sheep. When the woman becomes old the tilberi becomes a burden and the only way she can get rid of it, is to order it to gather all the sheepdropping in three highland pastures. Eager to get back on the nipple the tilberi will overexert itself and explode, leaving only a human rib beside the heap of droppings.
The milk-stealing tilberi is the only magic in Icelandic folklore that can only be performed by women. A fully grown tilberi could lie across a sheep´s back and suck two tits at the same time and when it would roll back to its farm it would spew the milk into its mother churn. The butter made from the milk would fall into little pieces if the magical sign smjörhnútur (butterknot) was drawn on it.
tilberinn sig, svo eftir liggur einungis mannsrifið úr kirkjugarðinum.
Að koma sér upp tilbera, eða snakk er eingöngu kvennagaldur og samkvæmt þjóðtrúnni þá notuðu konur hann til að draga björg í bú, en tilberinn hljóp út um haga að skipan móðurinnar og saug mjólk úr ám. Hann stökk upp á hrygg þeirra og saug þær með báðum hausum á sitthvorum enda búksins. Tilberamóðirin gerði svo smjör úr mjólkinni sem kallað er tilberasmjör.
Galdrastafurinn Smjörhnútur er notaður til að vita hvort tilberasmjör er borið á borð með því að rista hann í smjörstykkið. Ef það er tilberasmjör þá hjaðnar það niður eins og froða, eða springur í þúsund mola.