He is a medical anomaly, half human, half bat. As a result, he is often captured and escaping from various tormentors, many of whom are scientists, or associated with the United States government.
A famous front-page photo of Bat Boy, showing his grotesque screaming face has since evolved into a pop-culture image of sorts.
The story of Bat Boy was turned into a very successful and long-running off-Broadway musical known imaginatively as Bat Boy:The Musical.