Walpurgis Night

(väl-po͝orˈgĭs)

1. a. The eve of May Day, observed in some European countries and in some Scandinavian communities in the United States in celebration of spring and marked by music, singing, and bonfires.
   b. The eve of Beltane, believed by medieval Christians to be the occasion of a witches' Sabbath.
2. An episode or a situation having the quality of nightmarish wildness.