Prilkop, also known as the Black Man, is a former White Prophet.
Prilkop was once pale-skinned and white-haired with colorless eyes, much like the young Fool, but he darkened as his prophecies came true, to the point that his hair and skin became coal-black.
Prilkop was the White Prophet of the age that ended with the cataclysm in which dragons and Elderlings became functionally extinct. Guided by his last vision of the future, Prilkop waited on Aslevjal for the next White Prophet. He was present when Icefyre landed on the island, but was unable to persuade the dragon out of beginning his slow suicide. When the Pale Woman arrived, Prilkop initially believed she was a true White Prophet, and led her to Icefyre. Although Prilkop wants to thwart the Pale Woman's rise to power after realizing his mistake, he refrains from doing so, believing that it is the responsibility of a Catalyst.
During his time on Aslevjal, Prilkop became a semi-legendary figure to the Outislanders, who refer to him as the Black Man of Aslevjal. Many superstitions are associated with him, such as his acceptance or rejection of an offering being indicative of one's success consulting the dragon Icefyre. The Fool is fascinated by him as a prophet that has lived beyond the timeline of his prophecies.
Dutiful's contingent encounters Prilkop repeatedly after arriving on Aslevjal, though he does not interact with them beyond observing from afar. The Outislanders in the group are disturbed when their offerings for Prilkop are untouched the morning after being set out. Unbeknownst to them, Prilkop accepted an offering in the form of a pot of honey that Fitz had accidentally left outside his tent the night before.
Fitz and the Fool encounter Prilkop within the ice palace of the Pale Woman, and he appears to lead them directly into an ambush of her guards. After Fitz is released to slay Icefyre, Prilkop leads him back to Dutiful's campsite.
After Icefyre is freed, Prilkop leads Fitz and Thick to his home. He tells Fitz his story, but refuses to lead him back to the Pale Woman's palace, telling Fitz that as the Changer he alone is responsible for his own actions. Thick remains with Prilkop while Fitz recovers the Fool's body and brings him to the mountains. When they return to Aslevjal, the Black Man is shocked to see the Fool alive. Prilkop allows the Fool to stay with him to further recuperate. Prilkop also cautions Fitz against frequent use of the Skill-pillars, though he is unable to elaborate much on what consequences may occur.
Prilkop and the Fool decide to leave Aslevjal and return to their home in the southern lands to share their knowledge.
Prilkop was captured with the Fool when they returned to Clerres, and presumably tortured as well; the Fool assumes him dead or worse. However, Bee meets Prilkop in his cell when she arrives in Clerres. Prilkop is freed during her escape from the school.
After the destruction of the school by the dragons, Prilkop gathers to himself a few surviving citizens. He encounters the Fitz, who has just escaped from death, and feeds him. Prilkop bemoans the loss of the Servants' library and attempts to convince Fitz to help him restore the order. Prilkop believes that the collection and study of prophecy practiced by the Servants is a worthwhile cause, and that the Servants can function without corruption. He is left on Clerres with his next steps unknown.