The grandchild of Emperor Zeppelin. Rudolph is placed into the care of Van by Rosso and Viola, former waste gangers. Van agrees to help return Rudolph to the Guylos Empire capital, Guygalos, and to teach the boy how to pilot a Zoid properly. Although Rudolph's identity is initially kept hidden from Van and his friends, Doctor D. soon reveals the truth about the Crown Prince. Rudolph is an eager, friendly person, who wishes to be able to emulate Van in piloting skill. Rudolph is quite naive and prefers reasoning over fighting, even with Raven and Prozen. He also deeply cares for the Guylos empire and hates seeing others around him hurt.