Champion Jack (William Thomas) Dupree learned "Junker's Blues" as a child and recorded the tune in 1940. He was playing piano in Detroit when Joe Louis encouraged him to enter the boxing ring. That explains the nickname after he won The Golden Gloves and over one hundred bouts.
In 1949 Fats (Antoine) Domino changed the lyric of "Junker's Blues" and had his first hit with "The Fat Man" (Domino - Bartholomew) even though it was a B side.
Lloyd Price's "Lawdy Miss Clawdy" is the same melody as the previous two tunes. Fats Domino and Dave Bartholomew are in the backing band. The song topped the R&B charts in 1952.