To the great consternation of the Church, over the past 17 years veneration of a Mexican folk saint that personifies death has become the fastest-growing new religious movement in the West. At this point there are no systematic surveys of the precise number of Santa Muerte devotees, but based on 10 years of research in Mexico and the US, we estimate there are some 10 to 12 million followers, with a large majority in Mexico and a significant presence in the United States and Central America. However, the skeletal folk saint, whose name translates into English as both Saint Death and Holy Death, now has followers across the globe, including in the UK, where there are sufficient devotees to support a Facebook group specifically for British followers. As the name would indicate, Santa Muerte is a Mexican folk saint who personifies death. Whether as a plaster statue, votive candle, gold medallion or prayer card, she is most often depicted as a female Grim Reaper, wielding the same scythe and wearing a shroud similar to that of her male counterpart. She is also frequently shown with an owl, which in Mesoamerican traditions symbolises death. Unlike official saints, who have been canonised by the Catholic Church, folk saints are spirits of the dead considered holy by the local populace for their miracle-working powers. In Mexico and Latin America such folk saints as Niño Fidencio, Jesus Malverde, Maximon and San La Muerte (the Argentine counterpart of Santa Muerte) command widespread devotion and are often invoked more than the official saints. These folk saints are united to their devotees by nationality, cultural affinities, locality and social class. A Mexico City street vendor explained the appeal of Santa Muerte to us by saying: “She understands us because she is a battleaxe like us.” Where the Bony Lady, one of Santa Muerte’s many monikers, differs from other folk saints is that for most devotees she is the personification of death itself and not of a deceased human being. She is popular among cultural Catholics who don’t know, or care, that she is condemned by the Church. When Pope Francis visited Mexico for the first time in 2016, he rebuked the object of the fastest-growing new religious devotion in the Americas on his first full day in the country, thus ensuring that Catholics were aware of the Church’s stance. During a scathing castigation of his fellow bishops, the first New World pope disparaged Santa Muerte as a dangerous symbol of narco-culture: