Croak and Swagger

Nature Cat leads his friends to the pond for a day of listening to one of the most amazing spring sounds: the bullfrog croak! At the pond, amid the bullfrog croaks, the gang hears another sound: someone crying! Nature Cat finds the cries coming from Warren the Bullfrog, who is very sad because he doesn't know how to croak. What kind of bullfrog is he? It's up to Nature Cat and his pals to help Warren get his croak back!