Jo, Zette and JockoJo, Zette and Jocko.

The Adventures of Jo, Zette and Jocko is a Franco-Belgian comics series created by Hergé, the writer-artist best known for The Adventures of Tintin. The heroes of the series are two young children, brother and sister Jo and Zette Legrand, and their pet chimpanzee Jocko, plus their parents, Mr Legrand, Jo and Zette's father, aerospace engineer and designer, and Mrs Legrand, Jo and Zette's mother, housewife and Mr Legrand's wife. Jo, Zette and Jocko appear on the rear covers of some The Adventures of Tintin comic books, but never appear in the stories.