Initially, Ward de Ravet was cast as Zeppos, but he was ill when shooting started, so Senne Rouffaer took over the part. Because he was also directing, he had to be on the set every day anyway.
According to the original scenario, the Zeppos character regularly got into fist fights. Because this did not work for Senne Rouffaer, he suggested to make the character an English gentleman. The fist fights were replaced by fencing, something Senne knew quite well from classical theatre.
In the first season, Zeppos drove a jeep which was already considered spectacular at the time. In the second season he used an "Amphicar", a German amphibious passenger automobile, which became the Zeppos trademark.