Real children never appeared on the show, as this would have shattered the carefully crafted illusion that he was a child (the show's popularity overseas arose, in part, because audiences unfamiliar with British showbusiness believed he really was a child). So he discussed his pal Ozzie, and his schoolboy friends in the Black Hand Gang (who would punish any member caught in the company of a girl), but the characters he spoke about were never actually heard themselves.
The show's creators avoided using real children to maintain the illusion that the performer was a child, which contributed to its popularity overseas. He spoke about his friend Ozzie and his schoolmates in the Black Hand Gang, who enforced strict rules against girls, but these characters were never actually heard on the program.