Ah, Pogles’ Wood! A wonderful late 1960s BBC children’s TV series by Oliver Postgate and Peter Firmin. This tie-in book was published by Hamlyn in 1967 and is illustrated with a mix of stills from the TV series and drawings by Peter Firmin. (Firmin also created the puppets.)
In this story it’s Mrs Pogle’s birthday and Mr Pogle sends Pippin and Tog out to find something to make the filling for a birthday pie. When they spot a boy fishing they decide they’ll catch a fish to make a fish pie. As you’d expect though, things don’t go entirely to plan…