The Questing Beast is a Medieval creature that has received little scholarly attention. Because of her labile nature, she is difficult to identify and therefore challenging to study. When previously analyzed, she has been considered only in her Medieval context. By comparing the Questing Beast from Perlesvaus, the Post-Vulgate Cycle, and the Prose Tristan, four identifying characteristics can be found: she is symbolic, she is multi-formed, she is a mother that gives birth, and she produces a barking noise most often made by her unborn young. Of these four signs, the last is the most prevalent and identifiable. Using these traits and exploring the impact of Malory's Le Morte d'Arthur on post-Medieval authors, three developmentally important Renaissance Beast can be identified. Through comparison and critical analysis there is evidence that Errour and the Blatant Beast from Spenser's The Faerie Queene and Sin from Milton's Paradise Lost are descendants of the Medieval Beast. Her presence in Malory, Spenser, and Milton provides an unexplored link between Malory and Milton that opens Miltonian studies to further analysis through a Medieval lens. The Beast develops into an important character during the Renaissance, which allows her to influence Modern Arthurian authors and helps prove the importance of the Renaissance Questing Beasts and her continued prevalence in literature.