Naming ones self used to be a common practice among blues singers.

EG., Blind Willie McTell mentioned himself in 'Mr McTell's Got The Blues'. Muddy Waters did in 'Still a Fool', and in one of Robert Johnson's songs he calls himself 'Bob'.

I can't recall too many specific examples to mind right now, but Howlin' Wolf referred to himself as 'The Wolf' in several songs; Brownie McGhee did on at least one song, and I'm fairly certain that Charley Patton used his name in at least one Paramount recording.