"Joe Doakes" supposedly is a circus name that originated with P. T. Barnum.
2 April 1911, World (NY), Metropolitan section, pg. 2, col. 4:
BIG TOP LINGO.
The Jargon of the Circus Is Picturesque
and Hard to Understand.
The ringmaster for some unknown reason has been called "Joe Doakes" ever since the days of P. T. Barnum.