Scooby-Doo and Scooby-Doo 2 ) ::*Dave Coulier - did various voices on Scooby-Doo and Scrappy-Doo , and also imitated Scooby-Doo's voice a few times on Full House ::*Phyllis Diller - who had guest appearances on The animated television series ::*Don Knotts - who had guest appearances on The animated television series ::*Sarah