flagellant

Flagellants are practitioners of an extreme form of mortification of their own flesh by whipping it with various instruments. Most notably, Flagellantism was a 14th-century movement, consisting of radicals in the Catholic Church. It began as a militant pilgrimage and was later condemned by the Catholic Church as heretical. The followers were noted for including public flagellation in their rituals. https://en.wikipedia.org/wiki/Flagellant