Like a famous "Mr." of song, it was the nickname of tap dancer Bill Robinson
... Fred Astaire paid tribute to Bill Robinson in the tap routine "Bojangles 
of ... Bill Robinson's character was memorialized in Jerry Jeff Walker's 1968 song 
"Mr. [DOC] [TLE] Urban Dictionary: mr. Bo-Jangles [PAR] See Mr. Bojangles for the reference to the great dancer Bill Robinson.