Gyro is a cocky and flamboyant executioner marked by the harshness of life, who participates in the Steel Ball Run for the sake of a young boy.

Gyro initially appears as an aggressive contestant in the Steel Ball Run race. Unlike other competitors, Gyro looks to seize the first place above all else, rushing ahead of everyone[4] then fending off anyone who challenges him.[5][6] He also has a tendency to take dangerous shortcuts.[7][8] Gyro is a rude man, deriding the vast majority of those he meets with insults and mocking commentaries. Even with his closest friend Johnny Joestar, Gyro doesn't mince his words and sometimes argues with him. Moreover, Johnny only made a lasting impression on Gyro through his dogged stubborness[9] and otherwise looked down on him during their first meeting.[10] The only person for which Gyro had any degree of respect is his stern father Gregorio Zeppeli. Gyro's overconfidence extends to his fights, during which Gyro is prone to mock his enemies in some way or say something brash. For instance, he openly mocked Mountain Tim's "ridiculous" hat.