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
Shaggy & Scooby-Doo Get a Clue! on-the-run Uncle Albert. Another noticeable difference is that Shaggy now wears a white short-sleeved shirt with a green strip across the middle and green sleeves instead of his trademark green T-shirt. Frank Welker still does Scooby's voice. In addition, Shaggy and Scooby's cowardice tendencies have been considerably toned down. Much like "The 13 Ghosts of Scooby-Doo" on ABC in 1985 (which had actual ghosts and monsters) and the "Scooby-Doo and Scrappy-Doo" shorts in 1980, this show is different from the usual "crooks masquerading as ghosts and monsters" series. Fred Jones, Daphne Blake and Velma Dinkley are downgraded, but not completely