Zozi serves as the one who often gives good advice to Bartok and is a supportive partner to Bartok, although he did not like the fact that Bartok kept the ring that Prince Ivan gave him. He sees that a true hero doesn't take advantage of getting a reward, and thus tries to convince Bartok to give it back to Ivan.
In the scenes of the Skull, it shows he is quite experienced with riddles, especially the ones Bartok can't understand.