It's Lulu's birthday and she's decided she'd like a pet brontosaurus as a present. But when Lulu's parents tell her that's not possible, Lulu gets very upset. She does not like it when things don't go her way. So taking matters into her own hands Lulu storms off into the forest to find herself a new pet, all the way singing: I'm gonna, I'm gonna, I'm gonna, gonna, get a bronto-bronto-bronto-bronto-saurus for a pet! In the forest Lulu encounters a number of animals: a snake, a tiger, a bear, all of whom don't particularly impress her. And then she finds him... a beautiful, long-necked, gentle, graceful brontosaurus. And he completely agrees with Lulu that having a pet would be a wonderful thing indeed! Lulu thinks she's finally got her birthday wish. Until she realises that Mr Brontosaurus thinks that she would make an ideal pet for him! How will Lulu ever get out of this sticky situation without throwing a fit (Mr B does not respond well to those), or using force (Mr B is much too tall to bonk on the head with her suitcase), or smushing her sandwich?