Bud is streetwise and tough. He is insightful, creative and wise. Bud also has typical childhood fears. The depth of his character unfolds through many events in the story.
The reader sees Bud's streetwise, tough side as he navigates the hazards of the orphanage and foster homes. This side of Bud is most evident when he escapes the cruel, last foster home when they lock him outside in a shed. Bud escapes, vows never to return and while living on the streets, begins a journey to find who he believes is his father.
The insightful, creative, and wise side of Bud appears as the reader learns how Bud thinks. Bud keeps a book of many "rules to live by" and refers to them often. Many of these came directly from or were adapted from, things that his mother taught him. Bud's insight allows him to understand how others may feel in many situations. This insight allows him to act in ways that further his goals most of the time. Rather than take revenge on the cruel foster family's mother, Bud understands that it is only through showing the foster mother her son's true colors that he will help create a better environment for other foster children. He therefore acts to create a situation where the mother will see her son's imperfections.
Bud has normal, childhood fears despite his streetwise personality. He believes in vampires and fears waking up in unknown places without first attempting to listen and figure out what is going on around him.