Agent 'Z' and the Penguin From Mars

Agent Z And The Penguin From Mars was a 1996 Children's BBC sitcom, based on the book of the same name by Mark Haddon. Following the arrival of an unpleasant and dull new astronomer neighbour Dennis Sidebottom, a supposed lottery winner, the gang plot their biggest ever practical joke: an elaborate conspiracy involving a penguin stolen from a supermarket Christmas display, an alien from Mars, a spaceship and a "message for mankind" carved on a meteorite.