H. B. Tennison was born on February 12, 1930. He was 6'3" (1.9m) tall and weighed 130lbs (59kg). He was extremely shy and it was said by his sister, Mrs. Alys Jo Daniel, that he had a sunny disposition and that she does not remember him being a moody person. Tennison did not have many boy or girl companions. He played the trombone in the Arkansas High School band with Betty Jo Booker, but they were not friends. He was very fond of comic books and loved listening to radio shows, especially quiz programs.