dog and pony show
when the gang made a plan to lure out the villain by entering daphne & scoob in a dog show, daphne had of course assumed that scooby would be the contestant, and she would be posing as the owner. she assumed the contract she was signing was something perfunctory, having to do with scooby having all his shots or whatever, so she hadn't quite read it over, or understood just what kind of show it was