Wikipedia
Sorginak
Sorginak ( root form: sorgin, absolutive case (singular): sorgina) are the assistants of the goddess Mari in Basque mythology. It is also the Basque name for witches or pagan priestesses (though they could also be male), being difficult to discern between the mythological and real ones.
Sometimes sorginak are confused with lamiak (similar to nymphs). Along with them, and specially with Jentilak, sorginak are said often to have built the local megaliths.
Sorginak, like other European witches, used to participate in the sabbat, called akelarre locally. These mysteries happened on Friday nights, when Mari and Sugaar are said to meet in the locally sacred cave to engender storms.