A Franciscan friar turned Ustaše officer, Filipović occupies a particular place in the history of wartime atrocity — a man whose religious vocation did not restrain but appeared to coexist with, and then give way entirely to, documented participation in mass killing. His role at Jasenovac, one of the most lethal concentration camps operated by the Axis-aligned Independent State of Croatia, brought him into direct contact with systematic murder on a significant scale. The nickname his victims and guards assigned him was not a rhetorical flourish but a measure of how his conduct was perceived even within that environment.