Prokop Wiacki was a 17th-century orthodox saint known for his life as a holy fool. Born in 1578 near Khlynov (modern-day Kirov), he suffered mental impairment following a lightning strike in 1590. After being healed by Saint Tryphon at the Assumption Tryphon Monastery, he eventually embraced a life of wandering and holy folly. He is remembered for his prophetic abilities, which included foretelling illnesses, deaths, fires, and changes in taxation.