Wikipedia
Ferragut
Ferragut (also known as Ferragus, Ferracutus, Ferracute, Ferrakut, Ferraguto, Ferraù, Fernagu) was a character—a Saracen paladin, sometimes depicted as a giant—in texts dealing with the Matter of France, including the Historia Caroli Magni, and Italian romantic epics, such as Orlando innamorato by Matteo Maria Boiardo and Orlando furioso by Ludovico Ariosto. In the tales, he was portrayed as physically invulnerable except at his navel/stomach, and was eventually killed (or fated to be killed) by the paladin Roland.