The elderly Sully is the first other “eater” whom Maren encounters in the story. In Bones and All, eaters are united in their cannibalistic desires, though the exact nature of their cannibalism often varies. In addition to his cannibalism, Sully claims to have an ability to sense when a person is close to death, and he uses this secondary ability to consume those who have recently passed away. Sully therefore represents a more ethical mode of cannibalism, as he does not kill people and has no “victims,” but rather, only eats those who have already died of natural causes. The first person he ever consumed, he claims, was his own deceased grandfather. At an early age, he realized that he could not stay with his family, and he embarked on a long, solitary journey through the country, learning how to survive on his wiles, and even encountering other eaters throughout his travels. Sully’s advanced age shows that an eater can avoid detection for decades and live a long life if they are careful to cover their tracks.  

At first, Maren is surprised but relieved to discover that there are others like her, and she turns to Sully as a mentor figure. An old man with many decades of experience in rough living, Sully teaches Maren some important lessons in surviving on the fringes of a society that would condemn them both for their actions. Because Maren has been abandoned by her own family, she relies on Sully as something like a surrogate grandfather, looking to him for wisdom and a feeling of security amid her own tumultuous life. Despite his own insistence that eaters should stick to themselves, Sully seems to have a soft spot for Maren, and he gives her valuable information, shelter, and food. Another of Sully’s “grandfatherly” characteristics is his storytelling. He captivates Maren with colorful stories drawn from his own long and eventful life. He also has something of an artistic side. After he consumes someone, he cuts a strand of their hair and, using skills taught to him by his rope-maker father, adds it to a long rope of human-hair that he brings with him as a memento.  

Small details scattered throughout the story suggest that there is more to Sully than meets the eye, and Lee is particularly distrustful of the older man, though Maren places her trust in Sully and dismisses Lee’s concerns. Sully has a surprising tendency to show up when Maren needs him most, which strikes Lee as implausible and inconvenient. The end of the novel reveals that Sully’s kind and helpful facade conceals his own dark desires. After he attacks Maren, who is in fact his granddaughter, she injures him, and he continues to stalk her across the country in a weakened state. Sully never explains his own desire to consume his descendants, though his stubborn and ultimately self-destructive fixation with Maren hints at complex psychological motivations. In conversation with Maren, he suggests that he regards all children as a “mistake,” suggesting that he regrets having children and therefore bringing more eaters like himself into the world.