The show's main characters are three elementary school classroom pets — Linny the Guinea Pig, Turtle Tuck, and Ming-Ming Duckling. They are presented as a trio of heroes who rescue baby animals as they demonstrate the benefits of teamwork. Each episode follows a similar structure, with some variation, in terms of the storyline and the musical form. As each episode begins, viewers hear the school children, off-screen, leaving school at the end of the day. Once the classroom is vacant, a pencil holder rattles to create the ringing of a tin can telephone. Often, the classroom will be decorated with student artwork or other items related to the storyline, particular animal or geographic location of that episode. As the phone is ringing, the Wonder Pets make their way towards the phone.