The Moomins (1978)

S1E45 In Jail

Moomin, Fillyjonk, and the Snork Maiden remain blissfully unaware of their situation in jail. The park ranger, eager to catch a theatrical show, enlists his kind-hearted cousin to keep an eye on the trio. However, Moomin quickly manages to sway the cousin into believing in their innocence. Before long, the three friends find themselves free again.