Earlier, the brothers had founded a record company, Pathé Records, so the Pathé brothers were also serial entrepreneurs: starting multiple businesses. However, since only the second business concerned movie serials, they were not serial serial entrepreneurs.
After a falling out, Will Keith broke off on his own, forming the Battle Creek Toasted Corn Flake Company -- which became the Kellogg we still know today. Will Keith Kellogg was a serial cereal entreprenuer!
If only Dennis Hayes, founder of serial-modem seller Hayes Communications, would start a breakfast foods company. Then, he would be a serial serial-cereal entrepreneur.