Hans Freuhauf was a former Nazi scientist who was in charge of the Princeton Experiment. Some, including Marc McComber, believe that he was a member of a Gorr'Rylaehotep-related cult, although the Collective Knowledge implies that he operated separately from The Order.
Freuhauf, along with many of his former Nazi comrades, had an interest in mysticism and legends. During World War II, he utilised concentration camp detainees in experiments attempting to emulate a Gorr'Rylaehotep. After the end of the war, Freuhauf was acquisitioned by the United States government to work on their new space program. When he was given control of the research division by the government, he attempted to recreate an ancient Egyptian ritual by opening a Rift and summoning a Gorr'Rylaehotep using the information contained on an ancient tablet. However, when a Rift was eventually opened, the Slender Man appeared and killed everyone present, save for Marc McComber.