When Daphne takes the rest of the gang to meet her friend, famous voice over actor Frank Welker, they inadvertently find themselves in the middle of a very strange mystery full of several different monsters and several different actors! The gang meets voice over actors Frank Welker, Grey DeLisle-Griffin, Matthew Lillard and Kate Micucci, who have all gathered to do their job of recording an episode of a hit animated show that vaguely seems to be about four teenagers and their talking animal. But, when different monsters show up and start abducting various actors from the group, it looks like our gang has a real mystery on their hands, even more mysterious than how the actors' voices all sound strangely familiar to our gang. From Warner Bros. Animation, Scooby-Doo and Guess Who? focuses on the Mystery Inc. gang as they solve bigger mysteries while also encountering many memorable celebrities and pop culture stars. United States 2021.