Scooby-Doo on Zombie Island sequences of interplay between Shaggy and Scooby for him. After Don Messick's death, Scott Innes replaced Messick as the voice of Scooby-Doo. Casey Kasem did not reprise his role as Shaggy Rogers as he wished to only voice Shaggy if the character became a vegetarian, like himself. Instead, Billy West provided the voice for Shaggy. Mary Kay Bergman was cast as Daphne when the character was taken in a new direction. B.J. Ward, who played Velma in the "Johnny Bravo" crossover episode, reprised her role in this film. Frank Welker is the only actor from the original series to reprise
Scooby-Doo! and the Goblin King Shaggy are allowed to keep theirs as they have proven their courage. As morning comes, Fred, Daphne and Velma forget what transpired (due to the effects of the memory-erasing spell) as Shaggy and Scooby-Doo come to pick them up. As the carnival packs up, Scooby uses an unpacked mirror one last time to spook the gang as the film ends. Some monsters from "Scooby-Doo, Where Are You!", "The New Scooby-Doo Movies", "The Scooby-Doo Show", "Scooby-Doo and Scrappy-Doo", "What's New, Scooby-Doo?" and "Scooby-Doo! and the Legend of the Vampire" are sighted in this movie: Scooby-Doo! and the Goblin King Scooby-Doo and