Gregorio Zeppeli is a side character featured in Steel Ball Run who is Gyro's father and an executioner of the nation of Naples. Gregorio Zeppeli is a somber and serious man, whose loyalty lies in his king and his family. Stating that true happiness lies in the family, Gregorio considers that protecting and honoring one's family is one's true obligation. He has taught his eldest son Gyro everything he knows, wishing to impart all of his family's traditions and honor his ancestors' work.