Trivia: It is unclear whether Jack is Oggy's cousin or friend, but in the episode "Love and Kisses" (S2E81), it was shown that Jack instantly fell in love at first sight with Monica (Oggy's Sister), which tells us that Jack is indeed Oggy's friend. Making him Oggy's cousin means that Jack and Monica's relationship would be considered as familial marriage.
More trivia for Oggy and the Cockroaches
La guerre du mini golf - S3-E23
Question: Why was Jack laughing at the end of this episode after Oggy accidentally hit him with a pétanque ball?
Answer: It sounded like he was laughing, but he actually wasn't. Actually, he was getting nervous because he got gruesomely injured throughout this entire episode, and this was the last straw for him.